Table 1. Samples were cultured with 3 different techniques and compared to quantitative PCR (qPCR).
Biolumix had the lowest sensitivity failing to pick up 4/17 samples detected with other culture-based platforms. qPCR identified 2 samples that were not picked up by any other method. Positive qPCR samples were sequenced to identify the contributing signal. Highlighted samples fail the 10,000 CFU/g cutoffs which equates to a Cq of 26 on the qPCR assay according to the manufacturers’ instructions. (f) is fail or over 10,000 CFU/g. (p) is pass or under 10,000 CFU/g. The raw CFU numbers can be deduced by dividing the CFU number by the 1,000 fold dilution factor used in this study.
| Samples | Total Yeast and Mold (10,000 CFU/g = fail) | |||
|---|---|---|---|---|
| Simplate ® (CFU/g) | 3M ® (CFU/g) | BioLumix
®
(CFU/g) |
Cq | |
| KD4 | 0 | 0 | pass | 21.71 (f) |
| KD8 | 0 | 0 | pass | 22.5 (f) |
| PC3 | 0 | 0 | pass | >40 (p) |
| White Widow | 0 | 0 | pass | >40 (p) |
| KD1 | 0 | 0 | pass | 29.33 (p) |
| KD2 | 0 | 0 | pass | >40 (p) |
| KD3 | 0 | 0 | pass | 30.16 (p) |
| KD5 | 1000 (p) | 6000 (p) | pass | 27.76 (p) |
| KD6 | 3000 (p) | 19000 (f) | pass | 24.72 (f) |
| KD7 | 0 | 0 | pass | >40 (p) |
| Liberty Haze | 172000 (f) | 89000 (f) | pass | 24.02 (f) |
| Blueberry Kush | 0 | 0 | pass | 37.99 (p) |
| Blueberry Kush -spiked | >738,000 (f) | TNTC (f) | fail | 15.71 (f) |
| Girl Scout Cookies | >738,000 (f) | TNTC (f) | pass | 19.66 (f) |
| Jake's Grape | >738,000 (f) | TNTC (f) | pass | 24.56 (f) |
| Serious Happiness | 0 | 0 | pass | >40 (p) |
| White Rhino | 0 | 3000 (p) | pass | >40 (p) |
TNTC = Too Numerous To Count