title: GS20
design: The DNA quality was tested by 0.1% (w/v) agarose gel electrophoresis. The DNA purity and concentration were measured with a NanoDropTM 1000 spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). Two universal primers 338F (5-ACTCCTACGGGAGCAGCAG-3)-806R (5-GGACTACHGGGTWTCTAAT-3)