Abstract: Objective To develop the most suitable PCR system for ALDH2. Methods The orthogonal design was used to optimize PCR reaction system for ALDH2 with five factors(Taq DNA polymerase, Mg2+, DNA template, dNTPs and primers) at four levels respectively. Results The most suitable PCR system for ALDH2 was established, namely 25 L reaction system containing 2.5 L Mg2+(25mM), 2.0 L dNTPs mix(2.5mM), 3.0 L primers(2.5mM), 3.0 L DNA (~30ng), 2.5 μL of 10×PCR buffer, 1.5U of Taq DNA polymerase. The optimal annealing temperature was 60 based on gradient PCR. Conclusion This universal system provideda standardizing program for the ALDH2 gene polymorphism.

Key words: ALDH2, gene polymorphism, orthogonal design, PCR reaction system