Table 3.
Experimental output of L. monocytogenes cells obtained by hlyA-qPCR, hlyA—QX200 dPCR and hlyA—QuantStudio 3D dPCR.
| qPCRa | dPCR QX200b | dPCR QuantStudio 3Db | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dilution | Mean | SD | Signal ratioc | Mean | SD | Mean λ | Signal ratioc | Mean | SD | Mean λ | Signal ratioc | |
| IZSLER 133/1/16 | No dil | 4.93 × 106 | 1.35 × 106 | 4/4 | NT | NT | ||||||
| −1 | 5.33 × 105 | 8.78 × 104 | 4/4 | NT | NT | |||||||
| −2 | 5.94 × 104 | 1.55 × 103 | 4/4 | Saturated | Saturated | Saturated | 2/2 | Saturated | Saturated | 2/2 | ||
| −3 | 4.86 × 103 | 7.37 × 102 | 4/4 | 1.72 × 104 | 1.41 × 102 | 3.65 | 2/2 | 1.95 × 104 | / | 1/2 | ||
| −4 | 3.40 × 102 | 4.80 × 101 | 4/4 | 1.24 × 103 | 5.94 × 101 | 0.26 | 2/2 | 1.53 × 103 | 1.15 × 102 | 0.38 | 2/2 | |
| −5 | 2.89 × 101 | 2.07 × 100 | 4/4 | 1.30 × 102 | 1.98 × 100 | 0.03 | 2/2 | 1.90 × 102 | 2.53 × 100 | 0.05 | 2/2 | |
| −6 | 2.75 × 100 | 9.59 × 10−2 | 4/4 | 1.26 × 101 | 8.50 × 10−1 | 0.00 | 2/2 | 1.79 × 101 | 5.70 × 10−1 | 0.00 | 2/2 | |
| IZSLER 129516/1/16 | No dil | 3.00 × 106 | 1.26 × 105 | 4/4 | NT | NT | ||||||
| −1 | 2.31 × 105 | 1.05 × 104 | 4/4 | NT | NT | |||||||
| −2 | 2.32 × 104 | 2.98 × 103 | 4/4 | Saturated | Saturated | Saturated | 2/2 | Saturated | Saturated | 2/2 | ||
| −3 | 1.65 × 103 | 4.38 × 102 | 4/4 | 5.53 × 103 | 1.16 × 103 | 1.17 | 2/2 | 6.63 × 103 | 4.14 × 102 | 1.67 | 2/2 | |
| −4 | 1.58 × 102 | 5.32 × 101 | 4/4 | 6.94 × 102 | 8.49 × 100 | 0.15 | 2/2 | 7.48 × 102 | 9.18 × 101 | 0.19 | 2/2 | |
| −5 | 1.11 × 101 | 4.38 × 100 | 4/4 | 5.84 × 101 | 4.53 × 100 | 0.01 | 2/2 | 6.58 × 101 | 2.49 × 100 | 0.02 | 2/2 | |
| −6 | 1.07 × 100 | 6.60 × 10−1 | 4/4 | 5.84 × 100 | 1.92 × 100 | 0.00 | 2/2 | 7.86 × 100 | 6.90 × 10−2 | 0.00 | 2/2 | |
| IZSLER 424965/2/16 | No dil | 1.91 × 106 | 3.19 × 105 | 4/4 | NT | NT | ||||||
| −1 | 2.18 × 105 | 3.98 × 104 | 4/4 | NT | NT | |||||||
| −2 | 2.92 × 104 | 3.55 × 103 | 4/4 | Saturated | Saturated | Saturated | 2/2 | Saturated | Saturated | 2/2 | ||
| −3 | 2.16 × 103 | 1.66 × 102 | 4/4 | 8.20 × 103 | 1.78 × 102 | 1.74 | 2/2 | 5.82 × 103 | 5.59 × 103 | 1.46 | 2/2 | |
| −4 | 1.52 × 102 | 1.33 × 101 | 4/4 | 7.14 × 102 | 1.41 × 101 | 0.15 | 2/2 | 7.43 × 102 | 1.67 × 102 | 0.19 | 2/2 | |
| −5 | 1.45 × 101 | 1.39 × 10−1 | 4/4 | 8.02 × 101 | 5.37 | 0.02 | 2/2 | 9.0 × 101 | 1.05 × 101 | 0.02 | 2/2 | |
| −6 | 1.2 × 100 | 2.61 × 10−1 | 4/4 | 6.40 × 100 | 0 | 0.00 | 2/2 | 1.3 × 101 | 9.10 × 10−1 | 0.00 | 2/2 | |
| −7 | 6.45 × 10−2 | 1.21 × 10−2 | 4/4 | 1.04 × 100 | 6.80 × 10−1 | 0.00 | 2/2 | 1.44 × 100 | 2.00 × 10−1 | 0.00 | 2/2 | |
NT, not tested.
a
Number of L. monocytogenes cells/μL in the pure cultures/suspensions evaluated by hlyA-qPCR. Data are shown as mean and standard deviation of two qPCR runs in duplicated.
b
Number of L. monocytogenes cells/μL in the pure cultures/suspensions evaluated by hlyA-dPCRs. Data are shown as mean and standard deviation of one dPCR runs in duplicated for both dPCR platforms.
c
Number of positive or acceptable replicates/total number of replicates.