2.3.2. PCR reaction to amplify the aflD gene of aflatoxin-producing
moulds
A FAM labelled Nor-1 probe (QuantiFast pathogen PCR þ IC kit,
Qiagen, Whitehead Scientific) was used for PCR as suggested by the
manufacturer (Whitehead Scientific). Individual reactions had
2.5 ml of DNA sample solution hich was mixed with 5 ml master mix
(Taq DNA polymerase, dNTPs, MgCl2 and reaction buffers at optimal
concentrations for efficient amplication of DNA templates by PCR),
3.5 ml of the primers i.e nortaq-1 (1.75 ml), nortaq-2 (1.75 ml) each,
0.5 ml probe (0.5 nM) and 13.5 ml nuclease free water to make up a
reaction volume of 25 ml. The PCR was performed in eppendorf
tubes placed in 36-well rack of the GeneAmp 5700R Sequence
Detection RT-PCR System. Incubation proceeded for 2 min at 50 C
to allow for cleavage of uracil-Nglycosylase. AmpliTaq Gold acti-
vation was done by incubating for 10 min at 95 C. The following
temperature range of 95 C for 20 s, 55 C for 20 s and 72 C for 30 s
were used for the 35 PCR cycles.