Figure 1: Serum anti-PCC and anti-MCC Ab levels produced by C3H/HeN mice (H-2k) immunized with PCC. C3H/HeN mice (H-2k) were immunized with PCC emulsified in CFA, then immunized weekly for four weeks with PCC alone. Anti-PCC and anti-MCC Abs in serum were measured by ELISA before immunization and at two and four weeks after the start of immunization. ?: anti-PCC antibody titers in serum (n=5). ?: anti-MCC antibody titers in serum (n=5).