Antigenic components of Candida albicans were extracted from whole cells with a buffer containing SDS and 2-mercaptoethanol, and separated by SDS-polyacrylamide gel electrophoresis. The components reactive with IgG, IgA, IgM and IgE antibodies in sera from patients with (14 subjects) and without (15 subjects) C. albicans in the vagina, and from healthy females (34 subjects), were investigated by immunoblotting using immunoglobulin class-specific antibodies. Many components reacted with IgG and IgA in all sera tested; the major antigens that reacted strongly with the sera were 67, 62, 29 and 25 kDa components. Several components were observed which reacted with IgM in 63% of the sera; the 67, 62 and 25 kDa components that reacted with IgG and IgA also reacted with IgM. No components reacting with IgE were detected in any of the sera. No striking differences in antibody binding profiles to whole cell antigens were detected among the C. albicans positive and negative patients or the healthy subjects. On the other hand, IgG against extracellular proteinase was more frequently detected in the C. albicans positive patients than in the C. albicans negative group or the healthy subjects. This may suggest that vaginal infection with C. albicans contributes to a rise in anti-proteinase antibody levels.