Table 9. Inter-operator variability with two different extraction methods.
| Trizol LS with Preamplification | Qiagen miRNeasy w/o Preamplification | p-value | |||
|---|---|---|---|---|---|
| microRNAs | Mean |ΔΔCT|*(±SD) | # miRNA Not Expressed | Mean |ΔΔCT|*(±SD) | # miRNA Not Expressed | |
| miR-374 | 1.69 (±1.32) | 0 | 0.70 (±0.78) | 0 | 0.0006 |
| miR-142-3p | 1.69 (±1.83) | 0 | 0.91 (±0.89) | 0 | 0.0340 |
| miR-523 | 1.45 (±1.45) | 0 | 1.38 (±1.02) | 0 | 0.8240 |
| miR-374-5p | 1.69 (±1.73) | 5 | 1.27 (±1.06) | 0 | 0.2461 |
| miR-376c | 2.42 (±1.42) | 22 | 0.76 (±0.91) | 0 | <0.0001 |
| miR-27a | 1.29 (±1.23) | 6 | 0.98 (±1.03) | 0 | 0.2786 |
| miR-520d-5p | 2.05 (±2.03) | 31 | 1.20 (±1.01) | 1 | 0.0405 |
| miR-122 | 1.82 (±1.86) | 13 | 1.11 (±1.10) | 0 | 0.0642 |
| miR-485-3p | 1.45 (±1.45) | 0 | 1.50 (±1.01) | 0 | 0.8734 |
| miR-21 | 2.40 (±1.82) | 0 | 1.36 (±1.00) | 0 | 0.0062 |
| miR-218 | 1.77 (±1.79) | 32 | 1.09 (±1.06) | 0 | 0.0692 |
| Total | 1.79 (±1.63) | 109/704 = 15% a | 1.12 (±0.99) | 1/704 = 0.14% a | <0.0001 |
| p-value for Number of miRNAs Not Expressed a | <0.0001 | ||||
Differences in ΔΔCT between Qiagen miRNeasy with RNA carrier and no pre-amplification and Trizol LS with pre-amplification.
* |ΔΔCT| = Absolute Value [Operator 1 ΔCT—Operator 2 ΔCT].
Bold = statistically significant.
a = chi-squared test comparing number of miRNA not expressed using Trizol LS with preamplification as compared to using Qiagen miRNeasy without preamplification.