[Kinetic immunological-turbidimetric determination of C-3 protein with a fast analyzer (author's transl)]

A new immunological-turbidimetric method is described for the quantitative determination of individual proteins. It is based on initial rate analysis with fixed time kinetics. The optimal conditions for the analysis of C-3 protein are described, with respect to buffer composition, reaction time, the time interval for measurement of the initial rate, and the concentrations of antigen and antibody. With these optimised, standardised conditions, it is possible to obtain results for 29 samples in 20 seconds, using a reaction time of deltaA/15 seconds. The method is relatively accurate with a day to day variation coefficient of 4.3 for C-3 concentrations of 217.5 mg/l, and 6.4 for concentrations of 435 mg/l. It is therefore suitable for the clinical chemical laboratory. A detailed comparison of this with other methods, and its use in the measurement of patients' sera will be presented elsewhere.