The PCR reaction consisted
of 10 ll of Real Time 2 HS-PCR Mix SYBR A (A&A Biotechnology,
Poland), 1 ll of each forward and reverse primers (2 ll in the case
of mcrA), and 2 ll of DNA template (1 ng/ll), with sterile double
distilled water added to achieve a total volume of 20 ll. The initial
denaturation lasted 3 min at 95 C and was followed by 40 cycles
of the following incubation cycle: denaturation for 15 s at 95 C,
primer annealing for 30 s at 55 C (61 C for dsrA and mcrA), and
then product elongation for 30 s at 72 C. SYBR Green fluorescence
detection was performed at the end of each primer annealing step.
Amplicon specificity was confirmed via melting curve analysis of
the qPCR end products