The use of chromium-51 sodium chromate for the detection of food and chemical sensitivities.

Both antibody mediated lysis of human RBC's and toxic hemolysis were found to occur with chemicals used as coloring agents for foods, drugs and cosmetics. Because of the strong chromaticity of these dyes, chromium-51 sodium chromate was bound to the hemoglobin of target human RBC's and its efflux was used as an indicator of lysis instead of spectrophotometry, which had been used with food antigens. The major antibody effect was noted when treatment of the target RBC's with antiIgG resulted in a marked inhibition of lysis, indicating that IgG is a lysis-promoting factor (LPF) in this system. Weaker effects were noted by treatment of the target RBC's with monospecific antisera for the other four classes of immunoglobulin and for alpha2-macroglobulin. No neutralizing effects were observed by pre-incubation of the dyes with autologous serum prior to the addition of RBC's.