Rescue of the integrated plasmid and determination of the sequence of attB . The structure of the rescued plasmid, pMS98R, by digestion of genomic DNA from an S. coelicolor J1929 pMS98 exconjugant with StuI and self-ligation. The two primers PB3 and PB3rev were used to amplify the DNA reading out from the attL and attR sites produced on integration of pMS98 into the attB site. The PCR amplified DNA generated was separated by electrophoresis on a 0.8% agarose gel. The size of the band obtained is in agreement with the predicted 1548 bp fragment, after performing the manipulations in silico using the published S. coelicolor genome sequence .