C. Polymerase Chain Reaction-Random Amplified
Polymorphic DNA (PCR-RAPD)
Lactic acid bacteria isolated from beef Nham were randomly selected at least 20 colonies everyday
from day 1 to day 3 of fermentation for DNA fingerprint by RAPD technique using specific lactic acid bacteria Primer ; OPA – 3 (5’-AGTCAGCCAC-
3’) (Biodesign, U.S.A.) [12]. Synthesis of DNA products, using single lactic acid bacteria colony as DNA template, was performed in 25 µl reactions of Taq DNA polymerase (Vivantis, Malaysia) for DNA amplification. Reaction mix and PCR cycle program were prepared as suggested by the manufacturer except denaturing and annealing step for PCR was done at 94 °C, 5 min and at 36 °C, 1 min. PCR product were electrophoresed on 1.5% agarose gels stained with ethidiumbromide (1 µg/ml). The band pattern was visualized using gel documentation system (GeneGenius, U.S.A.).