Western immunoblot analysis of soluble (s) and insoluble (i) fractions of CVD 908-htrA expressing fragment C fused in-frame to a repitope of DT residues 186 to 201 or to tDT197. Membranes were probed with anti-DT or anti-FC antibodies. Lanes: T, pTETnir15; 1, pNO12; 2, pNO11; 3, pNO10; D, DT (5 pg).