Detection of IgE antibody-forming cells by passive cutaneous anaphylaxis using cell extract from lymphoid organs.

IgE and IgG2a antibody-forming cells in the lymphoid organs of rats were detected by passive cutaneous anaphylaxis (PCA) reaction using the extract from the tissue. The amount of antigen-specific IgE and IgG2a antibodies in the tissue extract could be expressed as PCA titers in which extract from 10(8) cells/ml was used as starting dilution. The total amount of antigen-specific IgE antibody produced in mouse IgE-producing hybridoma cells was calculated by maximum dilution of the extract to the minimal amount of IgE antibody inducing PCA reaction, i.e., 4 ng/ml. In the case of the extract from mouse IgE antibody-forming hybridomas, the minimal number of hybridoma cells to be detected by this method proved to be 2-3 X 10(4) cells/ml.