[Studies on staphylococcal enterotoxin B. 1. Quantitative assay by capillary tube single diffusion test (author's...

A method for rapidly identifying and quantitating small amount of staphylococcal enterotoxin B was developed on capillary tube single diffusion test. The high sensitivity of method has the advantages to save antiserum and incubation period. Some factors such as concentration of antigen and antiserum, incubation temperature, buffer systems, and position of capillary tube all might affect the test accuracy. If all those affecting factors were concerned, the toxin would probably be standardized. The most accessible quantitative estimation was accomplished by means of (1) plotting a precipitation curve from the different concentrations of standardized staphylococcal enterotoxin B; (2) the sample to be test was diluted by serial two-fold method with the same buffer system; (3) select suitable 3--5 dilutions to perform capillary tube diffusion test, taking the values of precipitation bands as abcissa and sample dilutions as longitudinal axis, rendered the precipitation curve of sample exquisitely paralled to that of the standard; (4) calibrate the figure values of sample exactly on the precipitation curve, and reading the toxin content of specimen to be tested from standard curve.