In order to determine the sensitivity limit of the multiplex
PCR method, mixtures of 10%-1% cattle, goat, horse,
donkey, pig, or chicken DNA in deer DNA were prepared.
An amount of 0.5 ng of DNA from each binary mixture
was analyzed. The quantification limit was estimated using
combined primer set to detect the 6 non-deer species.
Amounts as small as 0.01 ng (2%) of chicken DNA and
0.005 ng (1%) of the other 5 species DNA could be
detected and reliable quantification in a deer DNA sample
was achieved (Fig. 4). The Ct values corresponding to the
DNA percentage of the common species showed a linear
change, and correlation coefficient changes were between
0.94 and 0.99, indicating that multiplex PCR did not
compromise the sensitivity for detecting a single species
(Fig. 2). Accordingly, possible adulteration could be
effectively identified, even at a low level using a deerspecific
primer and the combined 6 other common species
primer set. The ratios of contamination for the 6 species
could be calculated using the equations in Fig. 4.