Growth and FITC labeling of Opa 52 E. coli and vector control E.coli E. coli Top10 containing pTrc99A (Amp) vector only or pTrc99A vector with an IPTG-inducible opa 52 gene were a kind gift from Dr. Scott Gray-Owen (University of Toronto, Canada). Frozen stocks were streaked on a LB plate containing 100 mg Ampicillin, and incubated at 37uC overnight. After 24 h, a single colony was picked and streaked on a LB/Ampicillin plate containing 0.1 mM IPTG, and incubated at 37uC overnight.