Why Microbial Testing Matters
Microbial contamination is not always visible — but it can halt distribution immediately if identified after retail release. Cannabis products can be exposed to molds, yeasts, and bacteria at multiple stages: during cultivation, drying, trimming, extraction, and packaging.
SQRD Lab applies validated PCR methods with enrichment broth to detect pathogens at low levels. We review results carefully before reporting, and communicate directly with your team when a finding warrants discussion before distribution decisions are made.
Pathogens & Organisms We Screen
Detection Method: PCR with Enrichment
Polymerase Chain Reaction (PCR) amplifies specific DNA sequences unique to each target pathogen. The enrichment broth step enhances sensitivity, ensuring even low-level contamination is reliably detected. This approach is both highly specific and rapidly completed.
Frequently Asked Questions
What usually causes a cannabis batch to fail microbial testing?
High humidity during drying, inadequate airflow, improper curing conditions, and cross-contamination during trimming or packaging are common contributors. Even short periods of uncontrolled moisture can significantly elevate microbial counts.
Can storage conditions after harvest affect microbial results?
Yes. Temperature fluctuations, elevated humidity, and improper packaging can allow microbial growth over time. Monitoring environmental controls throughout storage reduces unexpected findings at final testing.
If total yeast and mold counts are close to limits, should we be concerned?
Results near thresholds indicate environmental variability worth investigating. Reviewing drying protocols, facility sanitation, and airflow management often reveals the root cause and helps prevent future batches from exceeding action levels.
How can cultivation teams reduce microbial risk proactively?
Maintaining controlled humidity, ensuring proper drying timelines, implementing sanitation procedures, and minimizing plant contact all lower contamination risk. Preventive controls are consistently more effective than reactive remediation after a failed test.
What should operators review carefully on a microbial report?
Beyond pass/fail status, review colony counts relative to action limits, compare with previous batches, and identify any trends that may point to environmental control issues within the facility.
What organisms are screened in a cannabis microbial test?
California DCC-required microbial testing covers Salmonella spp., Shiga toxin-producing E. coli (STEC), four regulated Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus), and total yeast and mold counts. Salmonella and STEC are zero-tolerance pathogens — any detection constitutes an automatic failure.
Does cannabis microbial testing vary by product type?
Yes. California DCC sets different action limits for inhalable products (flower, vapes) versus ingestible products (edibles, tinctures, capsules). Ingestibles generally have stricter total yeast and mold thresholds because the oral route of exposure carries different health considerations than inhalation.
Ready to Screen for Microbial Contamination?
Contact our Los Angeles laboratory to schedule pickup and get results within 48–72 hours.