Sequencing success (%) for tissue samples preserved in silica-gel and collected from herbarium specimens (mean age 20 years). Green: plant tissue preserved in silica-gel. Olive: plant tissue collected from herbarium specimens. rbcL: one round of PCR with the primers rbcLa-F/rbcLa-R. matK: two consequent rounds of PCR with the primers matK-1RKIM-f/matK-3FKIM-r and matK_390f/matK_1326r (for the DNA samples failed in the first round). ITS2: one round of PCR with the primers ITS-S2F/ITS4.
Kuzmina et al. BMC Ecology 2012 12:25 doi:10.1186/1472-6785-12-25