The estimation of precipitating antibody using a turbidimetric technique.

The development of turbidity resulting from the precipitation between bovine serum albumin (BSA) and anti-BSA serum was studied in the spectrophotometer. Data obtained with the turbidimetric method correlated well with those obtained using the classical tube precipitin determination. The equivalence ratio and the concentration of precipitating antibody were determined turbidimetrically by a comparison of the data from both methods. Antibody concentration can be determined with this method in about 1 hour as compared with the 3 or more days required by the tube test. In addition, this technique requires substantially less reagent than other methods.