PCRs were performed with specific primers to determine presence of T-DNA segment of Riplasmid in the genomic DNA of V. officinalis hairy roots. The PCR with primers specific for rolB and rolC genes and template DNA from hairy roots amplified the expected bands of 450 and 700 bp,respectively (Figure 2) confirming the successful integration of T-DNA, while DNA templates from untransformed roots (used as control) did not show any amplification. The PCR analysis of hairy root clones also revealed that no band was amplified for virD2 gene (Figure 2c), indicating absence of A.rhizogenes ATCC 15834 contamination in the cultures.