Analyses of purified LPS from O-PS mutants by ELISA. The phenol-water-extracted LPS samples were adsorbed to wells of 96-well microtiter plates and detected using purified rabbit anti-A. actinomycetemcomitans antibodies. (A) WT, wild type (VT1169); rmlC, rhamnose epimerase mutant; rmlC/rlmC+, rhamnose epimerase complemented. (B) waaL, O-antigen ligase mutant; waaL/waaL+, O-antigen ligase complemented.