efficiency. The PCR efficiencies varied between 95 and 97 %. Only after automated DNA extraction from rapeseed, the PCR efficiency dropped to 89 %, which might be due to the high DNA content used in the PCR assay. The data are summarised in Table 2.
Routine samples
Maize, soya bean and rapeseed routine samples were analysed for the presence of small fragments of the reference genes hmga (maize), lectin (soya bean) or pepC (rapeseed) after automated DNA extraction and compared with results after manual DNA extraction. Cq values after automated DNA extraction were lower or similar compared with the manual procedure. For maize, Cq values of 22.73 ± 0.47 after automated DNA isolation and Cq values of 22.55 ± 0.33 after manual isolation were obtained. After automated DNA extraction of soya bean samples, Cq values of 22.51 ± 0.54 were obtained. These Cq values were slightly lower compared with the manual DNA extraction of the same soya bean samples (Cq = 24.74 ± 1.16). For the routine rapeseed samples, both isolation procedures were comparable, as qPCR analyses resulted in Cq values of 22.36 ± 0.85 (Maxwell) and 22.67 ± 0.22 (Wizard) (Fig. 4).