Micro-assay to measure the allergenicity of a Kunitz-type soybean trypsin inhibitor toward Balb/c mice by using RBL-2H3 cells.

The allergenicity of a Kunitz-type soybean trypsin inhibitor (KSTI) was investigated by a micro-assay of beta-N-acetylhexosaminidase released from RBL-2H3 cells primed with the anti-KSTI serum. KSTI stimulated the release of beta-N-acetylhexosaminidase from RBL-2H3 cells primed with the antiserum. The response of RBL-2H3 cells to the reaginic activity of the mouse anti-KSTI serum correlates fairly well with that by the passive cutaneous anaphylaxis (PCA) test, the sensitivity of both assays appearing to be similar. These results suggest that measuring the beta-N-acetylhexosaminidase released from RBL-2H3 is a convenient way for studying the allergen or the reaginic activity of a murine serum in place of the PCA test.