[Validity of quantitative protein A determination of "Staphylococcus aureus" by radial immunodiffusion].

The validity of quantitative determination of protein A by radial immunodiffusion has been tested using human serum, human IgG and porcine serum. The best results are obtained with porcine serum. Maximal sensitivity is obtained after 48 h of incubation with 15 microliters of porcine serum per 13 ml of gel. For these particular conditions the range of linearity varies between 20 and 300 microgram/ml.