Table 2.
Trueness of GMO quantification: comparison between NAIMA and qPCR
| Triplex platform | 35S/IVR NAIMA | 35S/IVR qPCR | Cv% between NAIMA and qPCR | Mon810/IVR NAIMA | Mon810/IVR qPCR | Cv% between NAIMA and qPCR |
|---|---|---|---|---|---|---|
| MON810 (IVR × 35S × Mon810) | 20.0 ± 8.1 | 25.7 ± 8.0 | 15.5 | 11.5 ± 5.0 | 8.7 ± 1.0 | 23.1 |
| 8.4 ± 6.0 | 11.5 ± 3.2 | 19.2 | 5.0 ± 2.1 | 5.0 ± 0.4 | 0.2 | |
| 7.4 ± 2.9 | 5.1 ± 0.6 | 32.6 | 2.6 ± 0.8 | 4.1 ± 0.4 | 25.2 | |
| 1.5 ± 0.7 | 3.9 ± 1.1 | 44.1 | 1.4 ± 0.6 | 1.2 ± 0.5 | 16.0 | |
| 0.9 ± 0.6 | 2.6 ± 0.8 | 45.7 | 0.3 ± 0.2 | 0.7 ± 0.3 | 37.4 | |
| 0.3 ± 0.2 | 0.6 ± 0.2 | 35.6 | 0.14 ± 0.11 | 0.13 ± 0.04 | 1.5 |
| Triplex platform | 35S/IVR NAIMA | 35S/IVR qPCR | Cv% between NAIMA and qPCR | tNOS/IVR NAIMA | tNOS/IVR qPCR | Cv% between NAIMA and qPCR |
|---|---|---|---|---|---|---|
| screening (IVR × 35S × tNOS)s | 17.1 ± 5.9 | 13.4 ± 4.3 | 20.0 | 10.9 ± 5.9 | 9.2 ± 3.4 | 12.9 |
| 12.6 ± 4.7 | 10.1 ± 1.7 | 17.7 | 9.6 ± 2.9 | 9.9 ± 1.0 | 2.3 | |
| 4.0 ± 1.8 | 6.2 ± 1.9 | 24.4 | 3.5 ± 0.6 | 3.4 ± 0.8 | 3.7 | |
| 0.9 ± 0.5 | 1.0 ± 0.4 | 6.1 | 0.6 ± 0.2 | 0.6 ± 0.2 | 2.4 | |
| 0.5 ± 0.2 | 0.4 ± 0.1 | 21.0 | 0.13 ± 0.13 | 0.3 ± 0.1 | 33.0 | |
| ND | 0.04* | ND | 0.00* | 0.02* | ND |
Both triplex platforms were evaluated for trueness of quantification on a series of maize samples containing different ratio of P35S, Mon810 and tNOS target copies in maize DNA from Mon810 and Mon863 GM maize background. Results of quantification were compared with those of singleplex qPCR analysis on the same samples.
Results are expressed as percentage of the transgenic element copy number (35S, tNOS or Mon810) in haploid genome (estimated by the IVR copy number).
*one of the amplifications has failed.
ND, not determined.