Cross Contamination – noun – “inadvertent transfer of bacteria or other contaminants from one surface, substance, etc., to another especially because of unsanitary handling procedures. – (Mariam Webster, 2021). Cross contamination is not a new concept in the clinical and food lab industries; many facilities have significant design aspects as well as SOPs to deliver the least amount of contaminants into the lab setting. For cannabis labs, however, often the exponential growth leads to a circumstance where the lab simply isn’t large enough for the number of samples processed and number of analytical instruments and personnel needed to process them. Cross contamination for cannabis labs can mean delayed results, heightened occurrences of false positives, and ultimately lost customers – why would you pay for analysis of your clean product in a dirty facility? The following steps can save you the headaches associated with cross contamination:
Wash (and dry) your hands properly
Flash back to early pandemic times when the Tik Tok “Ghen Co Vy” hand washing song was the hotness – we had little to no idea that the disease would be fueled mostly by aerosol transmission, but the premise is the same, good hand hygiene is good to reduce cross contamination. Hands are often the source of bacteria, both resident (here for the long haul; attached to your hands) and transient (easy to remove; just passing through), as they come into contact with surfaces from the bathroom to the pipettor daily (Robinson et al, 2016). Glove use coupled with adequate hand washing are good practices to reduce cross contamination from personnel to a product sample. Additionally, the type of hand drying technique can reduce the microbial load on the bathroom floors and, subsequently tracked into the lab. A 2013 study demonstrated almost double the contamination from air blade technology versus using a paper towel to dry your hands (Margas et al, 2013).
Design Your Lab for Separation
Microbes are migratory. In fact, E. coli can travel at speeds up to 15 body lengths per second. Compared to the fastest Olympians running the 4X100m relay, with an average speed of 35 feet per second or 6 body lengths, this bacterium is a gold medal winner, but we don’t want that in the lab setting (Milo and Phillips, 2021). New lab design keeps this idea of bacterial travel in mind, but for those labs without a new build, steps can be made to prevent contamination:
Try to keep traffic flow moving in one direction. Retracing steps can lead to contamination of a previous work station
Use separate equipment (e.g. cabinets, pipettes) for each process/step
Separate pre- and post-pcr areas
Physical separation – use different rooms, add walls, partitions, etc.
Establish, Train and Adhere to SOPs
Design SOPs that include everything- from hygiene to test procedures and sanitation.
High turnover for personnel in labs causes myriad issues. It doesn’t take long for a lab that is buttoned up with cohesive workflows to become a willy-nilly hodgepodge of poor lab practices. A lack of codified Standard Operating Procedures (SOPs) can lead to a lab rife with contaminants and no clear way to troubleshoot the issue. Labs should design strict SOPs that include everything from hand hygiene to test procedures and sanitation. Written SOPs, according to the WHO, should be available at all work stations in their most recent version in order to reduce biased results from testing (WHO, 2009). These SOPs should be relayed to each new employee and training on updated SOPs should be conducted on an ongoing basis. According to Sutton, 2010, laboratory SOPs can be broken down into the following categories:
Quality requirements
Media
Cultures
Equipment
Training
Sample handling
Lab operations
Testing methodology
Data handling/reporting/archiving
Investigations
Establish Controls and Monitor Results
Scanning electron micrograph shows a colony of Salmonella typhimurium bacteria. Photo courtesy of CDC, Janice Haney Carr
It may be difficult for labs to keep tabs on positivity and fail rates, but these are important aspects of a QC regimen. For microbiological analysis, labs should use an internal positive control to validate that 1) the method is working properly and 2) positives are a result of target analytes found in the target matrix, not an internal lab contamination strain. Positive controls can be an organism of choice, such as Salmonella Tranoroa, and can be tagged with a marker, such as Green Fluorescent Protein in order to differentiate the control strain. These controls will allow a lab tech to discriminate between a naturally contaminated specimen vs. a positive as a result of cross-contamination.
Labs should, in addition to having good QC practices, keep track of fail rates and positivity rates. This can be done as total lab results by analysis, but also can be broken down into customers. For instance, a lab fail rate for pesticides averages 4% for dried flower samples. If, during a given period of review, this rate jumps past 6% or falls below 2%, their may be an issue with instrumentation, personnel or the product itself. Once contamination is ruled out, labs can then present evidence of spikes in fail rates to growers who can then remediate in their own facilities. These efforts in concert will inherently drive down fail rates, increase lab capacity and efficiency, and result in cost savings for all parties associated.
Continuous Improvement is the Key
Cannabis testing labs are, compared to their food and clinical counterparts, relatively new. The lack of consistent state and federal regulation coupled with unfathomable growth each year, means many labs have been in the “build the plane as you fly” mode. As the lab environment matures, simple QC, SOP and hygiene changes can make an incremental differences and drive improvements for labs as well as growers and manufacturers they support. Lab management can, and should, take steps to reduce cross contamination, increase efficiency and lower costs; The first step is always the hardest, but continuous improvement cannot begin until it has been taken.
References
Margas, E, Maguire, E, Berland, C. R, Welander, F, & Holah, J. T. (2013). Assessment of the environmental microbiological cross contamination following hand drying with paper hand towels or an air blade dryer. Journal of Applied Microbiology, 115(2), 572-582.
Milo, M., and Phillips, R. (2021). How fast do cells move? Cell biology by the numbers. Retrieved from http://book.bionumbers.org/how-fast-do-cells-move/
Robinson, Andrew L, Lee, Hyun Jung, Kwon, Junehee, Todd, Ewen, Perez Rodriguez, Fernando, & Ryu, Dojin. (2016). Adequate Hand Washing and Glove Use Are Necessary To Reduce Cross-Contamination from Hands with High Bacterial Loads. Journal of Food Protection, 79(2), 304–308. https://doi.org/10.4315/0362-028X.JFP-15-342
Sutton, Scott. (2010). The importance of a strong SOP system in the QC microbiology lab. Journal of GXP Compliance, 14(2), 44.
World Health Organization. (2009). Good Laboratory Practice Handbook. Retrieved from https://www.who.int/tdr/publications/documents/glp-handbook.pdf
In this “Leaders in Cannabis Testing” series of articles, Green interviews cannabis testing laboratories and technology providers that are bringing unique perspectives to the industry. Particular attention is focused on how these businesses integrate innovative practices and technologies to navigate a rapidly changing landscape of regulatory constraints and B2B demand.
PathogenDx is an Arizona-based provider of microbial testing technologies. Since their inception in 2014, they have broadened their reach to 26 states in the US. In addition to cannabis product testing, PathogenDx also provides technologies for food safety testing, environmental testing and recently started offering human diagnostics testing to support COVID-19 response efforts.
We interviewed Milan Patel, CEO and co-founder of PathogenDx. Milan founded PathogenDx as a spin-off from one of his investments in a clinical diagnostics company testing for genetic markers in transplant organs. Prior to PathogenDx, Milan worked in finance and marketing at Intel and later served as CFO at Acentia (now Maximus Federal).
Aaron Green: What’s the history of PathogenDx?
Milan Patel: PathogenDx was effectively a spin-off of a clinical diagnostics company that my partner Dr. Mike Hogan, the inventor of the technology, had founded when he was a professor at the University of Arizona, but previously at Baylor Medical College back in 2002. I had invested in the company back then and I had realized that his technology had a broad and wide sweeping impact for testing – not just for pathogens in cannabis specifically, but also for pathogens in food, agriculture, water and even human diagnostics. In the last 14 months, this became very personal for every single person on the planet having been impacted by SARS-CoV-2, the viral pathogen causing Covid-19. The genesis of the company was just this, that human health, food and agricultural supply, and the environment has and will continue to be targeted by bacterial, fungal and viral pathogens impacting the safety and health of each human on the planet.
We founded PathogenDx and we pivoted the company from its original human organ transplant genetics market scope into the bigger markets; we felt the original focus was too niche for a technology with this much potential. We licensed the technology, and we repurposed it into primarily cannabis. We felt that achieving commercial success and use in the hands of cannabis testing labs at the state level where cannabis was first regulated was the most logical next step. Ultimately, our goal was and is to move into markets that are approved at the federal regulatory side of the spectrum, and that is where we are now.
Green: What year was that?
Milan Patel, CEO and Co-Founder of PathogenDx Photo credit: Michael Chansley
Patel: 2014.
Green: So, PathogenDx started in cannabis testing?
Patel: Yes, we started in cannabis testing. We now have over 100 labs that are using the technology. There is a specific need in cannabis when you’re looking at contamination or infection.
In the case of contamination on cannabis, you must look for bacterial and fungal organisms that make it unsafe, such as E. coli, or Salmonella or Aspergillus pathogens. We’re familiar with recent issues like the romaine lettuce foodborne illness outbreaks at Chipotle. In the case of fungal organisms such as Aspergillus, if you smoke or consume contaminated cannabis, it could have a huge impact on your health. Cannabis regulators realized that to ensure public health and safety there was more than just one pathogen – there were half a dozen of these bugs, at a minimum, that could be harmful to you.
The beauty of our technology, using a Microarray is that we can do what is called a multiplex test, which means you’re able to test for all bacterial and fungal pathogens in a single test, as opposed to the old “Adam Smith” model, which tests each pathogen on a one-by-one basis. The traditional approach is costly, time consuming and cumbersome. Cannabis is such a high value crop and producers need to get the answer quickly. Our tests can give a result in six hours on the same day, as opposed to the two or three days that it takes for these other approved methods on the market.
Green: What is your business model? Is there equipment in addition to consumables?
Patel: Our business model is the classic razor blade model. What that means is we sell equipment as well as the consumables – the testing kits themselves.
The PathogenDx technology uses standard, off-the-shelf lab equipment that you can find anywhere. We didn’t want to make the equipment proprietary so that a lab has to buy a specific OEM branded product. They can use almost any equipment that’s available commercially. We wanted to make sure that labs are only paying a fraction of the cost to get our equipment, as opposed to using other vendors. Secondly, the platform is open-ended, meaning it’s highly flexible to work with the volumes that different cannabis labs see daily, from high to low.
One equipment set can process many different types of testing kits. There are kits for regulated testing required by states, as well as required environmental contamination.
Green: Do you provide any in-house or reference lab testing?
Patel: We do. We have a CLIA lab for clinical testing. We did this about a year ago when we started doing COVID testing.
We don’t do any kind of in-house reference testing for cannabis, though we do use specific reference materials or standards from Emerald Scientific, for example, or from NCI. Our platform is all externally third-party reference lab tested whether it’s validated by our external cannabis lab customers or an independent lab. We want our customers to make sure that the actual test works in their own hands, in their own facility by their own people, as opposed to just shrugging our shoulders and saying, “hey, we’ve done it ourselves, believe us.” That’s the difference.
Green: Can you explain the difference between qPCR and endpoint PCR?
Patel: The difference between PathogenDx’s Microarray is it uses endpoint PCR versus qPCR (quantitative real time PCR). Effectively, our test doesn’t need to be enriched. Endpoint PCR delivers a higher level of accuracy, because when it goes to amplify that target DNA, whether it’s E. coli, Salmonella or Aspergillus pieces, it uses all the primer reagent to its endpoint. So, it amplifies every single piece of an E. Coli (for example) in that sample until the primer is fully consumed. In the case of qPCR, it basically reaches a threshold and then the reaction stops. That’s the difference which results in a much greater level of accuracy. This provides almost 10 times greater sensitivity to identify the pathogen in that sample.
The second thing is that we have separated out how the amplified sample hybridizes to the probe. In the case of our assay, we have a microarray with a well in it and we printed the actual probe that has the sequence of E. coli in there, now driving 100% specificity. Whereas in the qPCR, the reaction is not only amplifying, but it’s also basically working with the probe. So, in that way, we have a higher level of efficiency in terms of specificity. You get a definite answer exactly in terms of the organism you’re looking for.
In terms of an analogy, let’s take a zip code for example which has the extra four digits at the end of it. In the case of endpoint PCR, we have nine digits. We have our primer probes which represent the standard five digits of a zip code, and the physical location of the probe itself in the well which serves as the extra four digits of that zip code. The analyte must match both primary and secondary parts of the nine-digit zip code for it to lock in, like a key and a lock. And that’s the way our technology works in a nutshell.
Endpoint PCR is completely different. It drives higher levels of accuracy and specificity while reducing the turnaround time compared to qPCR – down to six hours from sample to result. In qPCR, you must enrich the sample for 24 to 48 hours, depending on bacteria or fungus, and then amplification and PCR analysis can be done in one to three hours. The accuracies and the turnaround times are the major differences between the endpoint PCR and qPCR.
Green: If I understand correctly, it’s a printed microarray in the well plate?
Patel: That’s correct. It’s a 96-well plate, and in each well, you’ve now printed all the probes for all targets in a single well. So, you’re not running more than one well per target, or per organism like you are for qPCR. You’re running just one well for all organisms. With our well plates, you’re consuming fewer wells and our patented foil-cover, you only use the wells you need. The unused wells in the well plate can be used in future tests, saving on costs and labor.
Green: Do you have any other differentiating IP?
The PathogenDx Microarray
Patel: The multiplex is the core IP. The way we process the raw sample, whether it’s flower or non-flower, without the need for enrichment is another part of the core IP. We do triplicate probes in each well for E. Coli, triplicate probes for Salmonella, etc., so there are three probes per targeted organism in each of the wells. We’re triple checking that you’re definitively identifying that bug at the end of the day. This is the cornerstone of our technology.
We were just approved by the State of New York, and the New York Department of Health has 13 different organisms for testing on cannabis. Think about it: one of the most rigorous testing requirements at a state level – maybe even at a federal level – and we just got approved for that. If you had to do 13 organisms separately, whether it’s plate culture or qPCR, it would become super expensive and very difficult. It would break the very backs of every testing lab to do that. That’s where the multiplexing becomes tremendously valuable because what you’re doing is leveraging the ability to do everything as a single test and single reaction.
Green: You mentioned New York. What other geographies are you active in?
Patel: We’re active in 26 different states including the major cannabis players: Florida, Nevada, California, Arizona, Michigan, New York, Oklahoma, Colorado and Washington – and we’re also in Canada. We’re currently working to enter other markets, but it all comes down to navigating the regulatory process and getting approval.
We’re not active currently in other international markets yet. We’re currently going through the AOAC approval process for our technology and I’m happy to say that we’re close to getting that in the next couple of months. Beyond that, I think we’ll scale more internationally.
I am delighted to say that we also got FDA EUA federal level authorization of our technology which drives significant credibility and confidence for the use of the technology. About a year ago, we made a conscious choice to make this technology federally acceptable by going into the COVID testing market. We got the FDA EUA back on April 20, ironically. That vote of confidence by the FDA means that our technology is capable of human testing. That has helped to create some runway in terms of getting federalized with both the FDA and the USDA, and certification by AOAC for our different tests.
Green: Was that COVID-19 EUA for clinical diagnostics or surveillance?
Patel: It was for clinical diagnostics, so it’s an actual human diagnostic test.
Green: Last couple of questions here. Once you find something as a cannabis operator, whether its bacteria or fungus, what can you do?
Patel: There are many services that are tied into our ecosystem. For example, we work with Willow Industries, who does remediation.
There’s been a lot of criticism around DNA based technology. It doesn’t matter if it’s qPCR or endpoint PCR. They say, “well, you’re also including dead organisms, dead DNA.” We do have a component of separating live versus dead DNA with a biomechanical process, using an enzyme that we’ve created, and it’s available commercially. Labs can test for whether a pathogen is living or dead and, in many cases, when they find it, they can partner with remediation companies to help address the issue at the grower level.
Another product we offer is an EnviroX test, which is an environmental test of air and surfaces. These have 50 pathogens in a single well. Think about this: these are all the bad actors that typically grow where soil is – the human pathogens, plant pathogens, powdery mildew, Botrytis, Fusarium – these are very problematic for the thousands of growers out there. The idea is to help them with screening technology before samples are pulled off the canopy and go to a regulated lab. We can help the growers isolate where that contamination is in that facility, then the remediation companies can come in, and help them save their crop and avoid economic losses.
Green: What are you most interested in learning about?
Patel: I would prefer that the cannabis industry not go through the same mistakes other industries have gone through. Cannabis started as a cottage industry. It’s obviously doubled every year, and as it gets scaled, the big corporations come in. Sophistication, standards, maturity all help in legitimacy of a business and image of an industry. At the end of the day, we have an opportunity to learn from other industries to really leapfrog and not have to go through the same mistakes. That’s one of the things that’s important to me. I’m very passionate about it.
One thing that I’ll leave you with is this: we’re dealing with more bugs in cannabis than the food industry. The food industry is only dealing with two to four bugs and look at the number of recalls they are navigating – and this is a multi-billion-dollar industry. Cannabis is still a fraction of that and we’re dealing with more bugs. We want to look ahead and avoid these recalls. How do you avoid some of the challenges around antimicrobial resistance and antibiotic resistance? We don’t want to be going down that road if we can avoid it and that’s sort of a personal mission for myself and the company.
Cannabis itself is so powerful, both medicinally as well as recreationally, and it can be beneficial for both consumers and industry image if we do the right things, and avoid future disasters, like the vaping crisis we went through 18 months ago because of bad GMPs. We must learn from those industries. We’re trying to make it better for the right reasons and that’s what’s important to me.
Green: Okay, great. That concludes the interview. Thank you, Milan.
Patel: Thank you for allowing me to share my thoughts and your time, Aaron.
Testing cannabis and cannabis derived products for microbiological contamination should be a straightforward conversation for testing labs and producers. However, a patchwork of regulations and a wide variety of perspectives on what we should, or should not, be looking for has left much of the cannabis industry searching for reliable answers.
Organizations like the AOAC are taking the first crack at creating standardization in the field but there is still a long way to go. In this conversation, we would like to discuss the general requirements that almost all states share and where we see the industry headed as jurisdictions start to conform to the recommendations of national organizations like AOAC.
We sat down with Anna Klavins and Jessa Youngblood, two cannabis testing experts at Hardy Diagnostics, to get their thoughts on microbiology testing in the current state of the cannabis industry.
Q: What are the biggest challenges facing cannabis testing labs when it comes to microbiology?
The CompactDry Yeast and Mold Rapid plate provides fast results.
Anna Klavins & Jessa Youngblood:For microbiology testing, it comes down to a lack of standardization and approved methods for cannabis. In the US, cannabis regulation is written on a state-by-state level. As a result, the rules that govern every aspect of bringing these materials to market is as unique and varied as the jurisdiction writing them. When we are speaking specifically about microbiology, the question always comes back to yeast and mold testing. For some, the challenge will often be centered on the four main Aspergillus species of concern – A. terreus, A. niger, A. fumigatus, and A. flavus. For others, it will be the challenges of total count testing with yeast, mold, and bacteria. These issues become even more troublesome by the lack of recognized standard methodology. Typically, we expect the FDA, USP, or some other agency to provide the guidelines for industry – the rules that define what is safe for consumption. Without federal guidance, however, we are often in a situation where labs are required to figure out how to perform these tests on their own. This becomes a very real hurdle for many programs.
Q: Why is it important to use two different technologies to achieve confirmation?
Dichloran Rose Bengal Chloramphenicol (DRBC) Agar is recommended for the enumeration of yeasts and molds.
Klavins & Youngblood: The push for this approach was borne out of the discussions happening within the industry. Scientists and specialists from across disciplines started getting together and creating groups to start to hash out problems which had arisen due to a lack of standardization. In regards to cannabis testing, implementing a single method for obtaining microbiology results could be unreliable. When clients compared results across labs, the inconsistencies became even more problematic and began to erode trust in the industry. As groups discussed the best way to prove the efficacy of their testing protocol, it quickly became apparent that relying on a single testing method was going to be inadequate. When labs use two different technologies for microbiology testing, they are able to eliminate the likelihood of false positives or false negatives, whichever the case may be. In essence, the cannabis testing laboratories would be best off looking into algorithms of detecting organisms of interest. This is the type of laboratory testing modeled in other industries and these models are starting make their way into the cannabis testing space. This approach is common in many food and pharma applications and makes sense for the fledgling cannabis market as well.
About Anna Klavins
Anna Klavins earned a Molecular and Cellular Biology B.S. degree from Cal Poly San Luis Obispo while playing for the Cal Poly Division I NCAA women’s tennis team. Since joining Hardy Diagnostics in mid-2016, she has gained experience in FDA submissions [510(k)] for class II microbiology in vitro devices. She has worked on 15 projects which led to a microbiology device becoming FDA cleared. She has recently begun participating in the AOAC Performance Tested Methods program.
About Jessa Youngblood
Jessa Youngblood is the Food, Beverage and Cannabis Market Coordinator for Hardy Diagnostics. A specialist in the field of cannabis microbiology for regulatory compliance, she is seated with the AOAC CASP committee working on standard methods for microbiological testing in cannabis and hemp. She also sits on the NCIA Scientific Advisory Council as well as the ASTM Cannabis Council.
SC Labs, a cannabis testing company with roots in Santa Cruz, California, announced this week that they have developed a comprehensive hemp testing panel that covers a number of contaminants on a national regulatory level. In the press release, the company says they aim to fill the void of national hemp testing requirements.
The hemp testing panel they have developed purportedly meets testing standards in states that require contaminant levels below a certain action limit. The SC Labs hemp testing panel could theoretically be used for regulatory compliance testing across the country, reaching action limits and analyte levels that meet the strictest state requirements.
The panel tests for pesticides, heavy metals, microbiology, mycotoxins, residual solvents and water activity.
The panel is one sign of progress on the long road to nationally harmonized testing standards. “As an industry, we’ve been advocating for national, standardized, and transparent testing regulations for years now,” says Jeff Gray, CEO of SC Labs. “The government has been slow to respond so we decided it was time to act. As an industry, we’ve been advocating for national, standardized, and transparent testing regulations for years now. The government has been slow to respond so we decided it was time to act.”
SC Labs is headquartered in Santa Cruz, but has licenses in California, Oregon, Texas and Colorado (pending). Their California and Oregon locations are both ISO 17025-accredited and conducting THC-containing cannabis testing, as well as hemp testing.
According to a press release published earlier this month, the Bio-Rad iQ-Check Aspergilllus Real-Time PCR Detection Kit has received AOAC International approval. The test covers detection for four different Aspergillus species: A. flavus, A. fumigatus, A. niger, and A. terreus.
The detection kit covers those Aspergillus species for testing in cannabis flower and cannabis concentrates, produced with our without solvents. The PCR detection kit was validated through the AOAC Research Institute’s Performance Tested Method Program. They conducted a study that resulted in “no significant difference” between the PCR detection kit and the reference method.
The iQ-Check Aspergillus Real-Time PCR Kit detects Aspergillus flavus, fumigatus, niger, and terreus in cannabis flower and cannabis concentrates.
The kit was evaluated on “robustness, product consistency, stability, inclusivity and exclusivity, and matrix studies,” the press release says. Bio-Rad also received approval and validation on the iQ-Check Free DNA Removal Solution, part of the workflow for testing cannabis flower.
The test kit uses gene amplification and real-time PCR detection. Following enrichment and DNA extraction, the test runs their PCR technology, then runs the CFX Manager IDE software to automatically generate and analyze results.
Bio’Rad has also recently received AOAC approval for other microbial testing methods in cannabis, including their iQ-Check Salmonella II, iQ-Check STEC VirX, and iQ-Check STEC SerO II PCR Detection Kits.
According to a press release published last week, Medicinal Genomics has hired Sherman Hom, Ph.D. to be their first director of regulatory affairs. Dr. Hom is coming from a position at New Jersey’s Division of Public Health and Environmental Laboratories (PHEL) where he was the leading research scientist for the state’s cannabis testing lab as well as coordinating their pre-analytical activities for SARS-CoV-2 testing.
Sherman Hom, Director of Regulatory Affairs at Medicinal Genomics
As project manager for the state’s cannabis testing lab, he was responsible for validating microbial testing in cannabis. He has also been a professor of microbiology, a lab manager, a senior research scientist, a writer and an inventor, according to the press release.
“My passion is regulatory affairs,” says Dr. Hom. “For the last 4 years, we’ve been building a facts and comparison database of required state medical cannabis testing. It’s formidable. Of course, the states will all have the same regulations eventually. In the meantime, it’s my job to help them craft the safest, most efficient and effective set of regulations possible. I’m here because I know Medicinal Genomics shares that passion.”
In a press release sent out this month, bioMérieux announced they have received the very first approvals in cannabis and hemp for AOAC Research Institute Performance Testing Methods (PTM). AOAC approved method validation for the detection of Salmonella and STEC (Shiga toxin-producing E. coli) in cannabis flower utilizing bioMérieux GENE- UP® SLM2 (PTM 121802) and EHEC (PTM 121806) assays.
According to the press release, these validations are the first of their kind in the cannabis and hemp industries. The AOAC-validated testing methods are approved for 1-gram and 10-gram samples.
Dr. Stan Bailey, senior director of scientific affairs at bioMérieux, says these approvals demonstrate the company’s commitment to innovative and validated science in the cannabis and hemp industries. “We are especially proud that the GENE-UP SLM2 and EHEC are the first two AOAC approvals in the United States for cannabis and hemp,” says Dr. Bailey. “This is increasingly important with now over half the population of the US living in states that have approved cannabis for recreational use and most states approving cannabis for medical use.”
The AOAC PTM designations are recognized by the US Department of Agriculture, the Food and Drug Administration, and global regulatory agencies. The validation guidance builds on AOAC’s Cannabis Analytical Science Program (CASP).
bioMérieux is a French in vitro diagnostics company that serves the global testing market. They provide diagnostic solutions such as systems, reagents, software and services.
Vintners have known for centuries that every step in the winemaking process—from cultivation and harvest techniques to fermentation, aging and bottling—has immense impact on the quality and value of the final product.
And that same level of scrutiny is now being applied to cannabis production.
As someone who has worked in the consumer-packaged goods (CPG) space for decades, I’ve been interested in finding out how post-harvest storage and packaging affect the quality and value of cannabis flower. After digging into the issue some more, storage conditions and humidity levels have indeed come into focus as major factors, beyond just the challenges of preventing mold.
Weighty Matters
I enlisted my research team at Boveda, which has studied moisture control in all manner of manufactured and natural CPG products, to look closer at what’s happening with cannabis once it leaves the cultivation room. There’s not a lot of research on cannabis storage—we checked—and so we explored this aspect further. We were frankly surprised by what a big effect evaporation has on quality and how this is playing out on the retail level.
We suspected moisture loss could affect the bottom line too, and so we did some number-crunching.
It’s well understood that the weight of cannabis flower directly correlates with its profitability—the heavier the yield, the higher the market value. Here’s what our analysis found: A mere 5% dip below the optimal relative humidity (RH) storage environment eliminates six pounds per every 1,000 pounds of cannabis flower. At $5 per gram wholesale, that works out to upwards of $13,500 in lost revenue—and that’s with just a 5% drop in RH below the target range of 55-65% established by ASTM International, an independent industry standards organization.
We also purchased flower at retailers in multiple state markets and commissioned a lab to test the samples, which revealed that most strains sold today are well below the optimal RH range (55-65%). Regardless of fluctuating wholesale prices, when you do the math it’s clear that tens of thousands of dollars in revenue are simply evaporating into thin air.
Why So Dry?
Historically, cultivators, processors and packagers have emphasized keeping flower below a particular humidity “ceiling” for a reason: Flower that’s too moist is prone to hazardous mold and microbial growth, so it’s understandable that many operators err on the side of being overly dry.
The misconception that cannabis flower can be “rehydrated” is another cause of dryness damage. But this method irrevocably damages the quality of the flower through trichome damage.
The fine outgrowths, referred to as trichomes, house the majority of the plant’s resin
Those delicate plant structures that house the all-important cannabinoids and terpenes become brittle and fragile when stored in an overly dry environment, and are prone to breaking off from the flower; they cannot not be recovered even if the flower is later rehydrated.
When trichomes are compromised, terpenes responsible for the aroma, taste and scent of cannabis also can evaporate. Overly dried-out cannabis doesn’t just lose weight and efficacy—it loses shelf appeal, which is particularly risky in today’s market.
Today’s consumers have an appreciation for how premium flower should look, smell and taste. Rehydration cannot put terpenes back in the flower, nor can it re-attach trichomes to the flower, which is why preservation of these elements is so key.
Cannabis Humidity Control
Cured cannabis flower can remain in storage potentially for months prior to sale or consumption. By the time it reaches the end consumer, much of the cannabis sold in regulated environments in the U.S. and Canada has suffered from dry damage.
Rows of cannabis plants drying and curing following harvest
There are various humidity controls available for cannabis cultivators: desiccants that absorb water vapor; mechanical equipment that alters RH on a larger scale; or two-way humidity-control packets designed for storage containers.
In the CPG sector, with other moisture-sensitive products such as foods and electronics, we’ve seen that employing humidity controls will preserve quality, and cannabis flower is no different.
Saltwater-based humidity control solutions with two-way vapor-phase osmosis technology automatically add or remove water vapor as needed to maintain a constant, predetermined RH level and ensures a consistent level of moisture weight inside the cannabis flower.
Here’s one more notable finding we discovered in our storage research: Third-party lab tests commissioned by Boveda showed cannabis stored with humidity control had terpene and cannabinoid levels that were 15% higher than cannabis stored without.
Cannabis stored within the optimal humidity range maximizes all the qualities that attract and retain customers. Similar to wine-making, when cannabis cultivators focus on quality control they need to look beyond the harvest.
In 1887, Julius Petri invented a couple of glass dishes, designed to grow bacteria in a reproducible, consistent environment. The Petri dish, as it came to be known, birthed the scientific practice of agar cultures, allowing scientists to study bacteria and viruses. The field of microbiology was able to flourish with this handy new tool. The Petri dish, along with advancements in our understanding of microbiology, later developed into the modern field of microbial testing, allowing scientists to understand and measure microbial colonies to detect harmful pathogens in our food and water, like E. coli and Salmonella, for example.
The global food supply chain moves much faster today than it did in the late 19th century. According to Milan Patel, CEO of PathogenDx, this calls for something a little quicker. “Traditional microbial testing is tedious and lengthy,” says Patel. “We need 21st century pathogen detection solutions.”
Milan Patel first joined the parent company of PathogenDx back in 2012, when they were more focused on clinical diagnostics. “The company was predominantly built on grant funding [a $12 million grant from the National Institute of Health] and focused on a niche market that was very specialized and small in terms of market size and opportunity,” says Patel. “I realized that the technology had a much greater opportunity in a larger market.”
Milan Patel, CEO of PathogenDx Photo: Michael Chansley
He thought that other markets could benefit from that technology greatly, so the parent company licensed the technology and that is how PathogenDx was formed. Him and his team wanted to bring the product to market without having to obtain FDA regulatory approval, so they looked to the cannabis market. “What we realized was we were solving a ‘massive’ bottleneck issue where the microbial test was the ‘longest test’ out of all the tests required in that industry, taking 3-6 days,” says Patel. “We ultimately realized that this challenge was endemic in every market – food, agriculture, water, etc. – and that the world was using a 140-year-old solution in the form of petri dish testing for microbial organisms to address challenges of industries and markets demanding faster turnaround of results, better accuracy, and lower cost- and that is the technology PathogenDx has invented and developed.”
While originally a spinoff technology designed for clinical diagnostics, they deployed the technology in cannabis testing labs early on. The purpose was to simplify the process of testing in an easy approach, with an ultra-low cost and higher throughput. Their technology delivers microbial results in less than 6 hours compared to 24-36 hours for next best option.
The PathogenDx Microarray
Out of all the tests performed in a licensed cannabis testing laboratory, microbial tests are the longest, sometimes taking up to a few days. “Other tests in the laboratory can usually be done in 2-4 hours, so growers would never get their microbial testing results on time,” says Patel. “We developed this technology that gets results in 6 hours. The FDA has never seen something like this. It is a very disruptive technology.”
When it comes to microbial contamination, timing is everything. “By the time Petri dish results are in, the supply chain is already in motion and products are moving downstream to distributors and retailers,” Patel says. “With a 6-hour turnaround time, we can identify where exactly in the supply chain contaminant is occurring and spreading.”
The technology is easy to use for a lab technician, which allows for a standard process on one platform that is accurate, consistent and reproduceable. The technology can deliver results with essentially just 12 steps:
Take 1 gram of cannabis flower or non-flower sample. Or take environmental swab
Drop sample in solution. Swab should already be in solution
Vortex
Transfer 1ml of solution into 1.5ml tube
A look at how the sample is added to the microarray
Conduct two 3-minute centrifugation steps to separate leaf material, free-floating DNA and create a small pellet with live cells
Conduct cell lysis by adding digestion buffer to sample on heat blocks for 1 hour
Conduct Loci enhancement PCR of sample for 1 hour
Conduct Labelling PCR which essentially attaches a fluorescent tag on the analyte DNA for 1 hour
Pipette into the Multiplex microarray well where hybridization of sample to probes for 30 minutes
Conduct wash cycle for 15 minutes
Dry and image the slide in imager
The imager will create a TIFF file where software will analyze and deliver results and a report
Their DetectX product can test for a number of pathogens in parallel in the same sample at the same time down to 1 colony forming unit (CFU) per gram. For bacteria, the bacterial kit can detect E. coli, E. coli/Shigella spp., Salmonella enterica, Listeria and Staph aureus, Stec 1 and Stec 2 E.coli. For yeast and mold, the fungal kit can test for Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus.
Their QuantX is the world’s first and only multiplex quantification microarray product that can quantify the microbial contamination load for key organisms such as total aerobic bacteria, total yeast & mold, bile tolerant gram negative, total coliform and total Enterobacteriaceae over a dynamic range from 100 CFU/mL up to 1,000,000 CFU/mL.
Not all of the PathogenDx technology is designed for just microbial testing of cannabis or food products. Their EnviroX technology is designed to help growers, processors or producers across any industry identify areas of microbial contamination, being used as a tool for quality assurance and hazard analysis. They conducted industry-wide surveys of the pathogens that are creating problems for cultivators and came up with a list of more than 50 bacterial and fungal pathogens that the EnviroX assay can test for to help growers identify contamination hotspots in their facilities.
Using the EnviroX assay, growers can swab surfaces like vents, fans, racks, workbenches and other potential areas of contamination where plants come in contact. This helps growers identify potential areas of contamination and remediate those locations. Patel says the tool could help growers employ more efficient standard operating procedures with sanitation and sterilization, reducing the facility’s incidence of pathogens winding up on crops, as well as reduction in use of pesticides and fungicides on the product.
Deploying this technology in the cannabis industry allowed Milan Patel and the PathogenDx team to bring something new to the world of microbial testing. Their products are now in more than 90 laboratories throughout the country. The success of this technology provides another shining example of how the cannabis market produces innovative and disruptive ideas that have a major impact on the world, far beyond cannabis itself.
To reinforce the ideas in the article, Sanitation Starting Points: More Than Sweeping the Floors and Wiping Down the Table, the main goal of sanitation is to produce safe food and to keep consumers healthy and safe from foodborne illness. With the cannabis industry growing rapidly, cannabis reaches a larger, wider audience. This population includes consumers most vulnerable to foodborne illness such as people with immunocompromised systems, the elderly, the pregnant, or the young. These consumers, and all consumers, need and deserve safe cannabis products every experience.
Sanitation is not an innate characteristic; rather, sanitation is a trained skill. To carry out proper sanitation, training on proper sanitation practices needs to be provided. Every cannabis food manufacturing facility should require and value a written sanitation program. However, a written program naturally needs to be carried out by people. Hiring experienced experts may be one solution and developing non-specialists into an effective team is an alternative solution. Note that it takes every member of the team, even those without “sanitation” in their title, to carry out an effective sanitation program.
Sanitation is a part of the Food and Drug Administration’s Code of Federal Regulations on current Good Manufacturing Practices (GMPs) in manufacturing, packing or holding human food (21 CFR 110). Sanitation starts at the beginning of a food manufacturing process; even before we are ready to work, there are microorganisms, or microbes, present on the work surfaces. What are microbes? At a very basic level, the effects of microbes can be categorized into the good, the bad, and the ugly. The beneficial effects are when microbes are used to produce cheese, beer or yogurt. On the other hand, microbes can have undesirable effects that spoil food, altering the quality aspects such as taste or visual appeal. The last category are microbes that have consequences such as illness, organ failure and even death.In a food manufacturing facility, minimizing microbes at the beginning of the process increases the chance of producing safe food.
Proper sanitation training allows cannabis food manufacturing facilities to maintain a clean environment to prevent foodborne illness from affecting human health. Sanitation training can be as basic or as complex as the company and its processes; as such, sanitation training must evolve alongside the company’s growth. Here are five key talking points to cover in a basic sanitation training program for any facility.
Provide the “why” of sanitation. While Simon Sinek’s TEDx talk “Start with why” is geared more towards leadership, the essential message that “Whether individuals or organizations, we follow those who lead not because we have to, but because we want to.” Merely paying someone to complete a task will not always yield the same results as inspiring someone to care about their work. Providing examples of the importance of sanitation in keeping people healthy and safe will impart a deeper motivation for all to practice proper sanitation. An entertaining illustration for the “why” is to share that scientists at the University of Arizona found that cellphones can carry ten times more bacteria than toilet seats!
Define cleaning and sanitizing. Cleaning does not equal sanitizing. Cleaning merely removes visible soil from a surface while sanitizing reduces the number of microorganisms on the clean surface to safe levels. For an effective sanitation system, first clean then sanitize all utensils and food-contact surfaces of equipment before use (FDA Food Code 2017 4-7).
Explain from the ground up. Instead of jumping into the training of cleaning a specific piece of equipment, start training with the foundational aspects of food safety. For example, a basic instruction on microbiology and microorganisms will lay down the foundation for all future training. Understanding that FATTOM (the acronym for food, acidity, temperature, time, oxygen and moisture) are the variables that any microorganism needs to grow supplies people with the tools to understand how to prevent microorganisms from growing. Furthermore, explaining the basics such as the common foodborne illnesses can reinforce the “why” of sanitation.
PPE for all employees at every stage of processing is essential
Inform about the principles of chemistry and chemicals. A basic introduction to chemicals and the pH scale can go a long way in having the knowledge to prevent mixing incompatible chemicals, prevent damaging surfaces, or prevent hurting people. Additionally, proper concentration (i.e. dilution) is key in the effectiveness of the cleaning chemicals.
Ensure the training is relevant and applicable to your company. Direct proper sanitation practices with a strong master sanitation schedule and ensure accountability with daily, weekly, monthly and annual logs. Develop sanitation standard operating procedures (SSOPs), maintain safety data sheets (SDS’s) and dispense proper protective equipment (PPE).
Overall, sanitation is everyone’s job. All employees at all levels will benefit from learning about proper sanitation practices. As such, it is beneficial to incorporate sanitation practices into cannabis food manufacturing processes from the beginning. Protect your brand from product rework or recalls and, most importantly, protect your consumers from foodborne illness, by practicing proper sanitation.
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Flash back to early pandemic times when the Tik Tok “Ghen Co Vy” hand washing song was the hotness – we had little to no idea that the disease would be fueled mostly by aerosol transmission, but the premise is the same, good hand hygiene is good to reduce cross contamination. Hands are often the source of bacteria, both resident (here for the long haul; attached to your hands) and transient (easy to remove; just passing through), as they come into contact with surfaces from the bathroom to the pipettor daily (Robinson et al, 2016). Glove use coupled with adequate hand washing are good practices to reduce cross contamination from personnel to a product sample. Additionally, the type of hand drying technique can reduce the microbial load on the bathroom floors and, subsequently tracked into the lab. A 2013 study demonstrated almost double the contamination from air blade technology versus using a paper towel to dry your hands (Margas et al, 2013).
