PCR products were visualized by blue light after electrophoresis on a 2.5 %
agarose gel containing 1 × GelStar ® Nucleic Acid Gel Stain (Lonza, Breda, The Netherlands) in 1 × Tris - borate buffer (pH 8.0).
The amplified DNA products were analyzed on a 1.0 %
agarose gel, and pieces of
gel containing the amplified DNA bands were excised and purified using a
gel extraction kit (Takara Bio).