Primer pair specificity was tested by amplification of the target
in 10 ng reference material gDNA. A sample is considered as positive
if a specific signal is generated with a SYBR_Green qPCR
method according to the following criteria: (1) (exponential)
amplification (increase of fluorescence) should be obtained using
template DNA containing the target sequence(s), while negative
controls (No Template Controls (NTC) and/or gDNA from
non-target-plants) do not yield amplification. (2) For all positive
reactions, the obtained PCR product should represents a single
peak in melting analysis with a unique Tm value corresponding
to the nominal Tm value obtained for the corresponding Sybric on
or pENGL template (with an acceptable difference of ±1 C), while
no specific peaks should be detectable in the negative controls.
Also (3), a single band should be obtained in agarose gel analysis
with a molecular weight corresponding to the predicted amplicons
size (SD ± 10 bp). All these criteria were assessed with the developed
primers (Fig. 3).