Western blot analysis of antibody responses generated following immunization with recombinant Msg. Panel A shows a Coomassie blue-stained gel and panel B shows western blots using sera from 2 immunized mice and 1 control mouse. For both the gel and the blots, lane 1 utilized a crude Pneumocystis antigen extract, while lane 2 utilized purified Msg. For the western blots, the serum used to probe the blots is shown under the blot. 107Am is from an animal that received 4 immunizations with MSG107Am, and 119Am is from an animal that received 4 immunizations with MSG119Am. No Ag is from an animal immunized with adjuvant alone. Brackets indicate the location of Msg. The Msg in purified preparations is smaller than in crude preparations because lyticase treatment, which is used to solubilize Msg, results in a decrease in the apparent molecular weight of Msg.