Medicinal Genomics has developed a test that costs about $5 per sample and has specificity of 96.3% for bacterial and 99.97% for fungal contaminants. Massachusetts standards for marijuana safety testing are based on the American Herbal Pharmacopoeia and look for total aerobic colony count, total yeast and mold, biotolerant gram-negative, E. coli, Salmonella, and coliforms.