[Radioimmunological differentiation of yeasts (author's transl)]

A microtiter solid phase radioimmunoassay is described for the differentiation or microorganisms by using six species of yeasts as a model. Rabbits were immunized with homogenized cells of the yeasts. The rabbit sera obtained were absorbed to homologous cells and after elution, the antibodies so obtained were labeled with 125I. Cross-reacting antibodies were eliminated by absorption to the corresponding yeast cells (table 1). With this radioimmunoassay it was possible to identify 51 out of 52 strains of C. albicans, C. tropicalis, C. pseudotropicalis, C. krusei, Torulopsis glabrata and Geotrichum candidum (table 2), whereas only 30 out of 52 strains could be differentiated by the conventional agglutination procedure (table 3). In the radioimmunoassay four immunoglobulin preparations directed against C. tropicalis, C. krusei, Torulopsis glabrata and Geotrichum candidum reacted only with the corresponding species. The immunoglobulin preparation directed against C. albicans reacted both with C. albicans and C. tropicalis and the preparation directed against C. pseudotropicalis reacted with C. pseudotropicalis and C. krusei (fig. 1). None of 60 isolates of 10 species of bacteria cross-reacted with the six yeast antisera, when tested in the radioimmunoassay.