DNA isolation, optimization of ISSR-PCR system and primers screening of Scutellaria baicalensis

To estimate genetic diversity and to authenticate the medicinal materials of Scutellaria baicalensis Georgi, the present work including DNA isolation, optimization of PCR assay of inter-simple sequence repeat (ISSR) and primers screening were investigated. Among three DNA isolation methods, improved CTAB, improved SDS and isolation kit, the improved CTAB was the best if restricted by funding. Based on selection design and protocols of reports, the optimal ISSR-PCR action was carried out in a volume of 20 mu l containing 20 ng of DNA template, 1.0 U of Taq DNA polymerase, 1 x buffer, 200 mu M dNTPs, 0.2 mu M of primer and 2.25 mu M Mg(2+). According to this PCR system, fifteen out of one hundred primers were chosen for their high clarity and repetition.