Evaluation of quantitative methods for determination of protein in urine

The automated immunoprecipitin reaction (A.I.P.) and the Laurell electroimmuno assay (rocket electrophoresis) are applied to unconcentrated overnight urines from patients hospitalised for various diseases, including both Albustix-positive and Albustix-negative samples. The results of both methods and the results of a quantitative determination of total protein are compared. The correlation coefficients between the two immunochemical methods are good, with a significance level of p less than 0.01 for all r-values. The correlation coefficient between the immunochemical methods and the quantitative determination of total protein is dependent on the amount of protein excreted in the urine. If urines should be examined for proteins we recommend a quantitative screening method or an immunochemical determination of albumin. For the latter we find that the A.I.P.-reaction is the method of choice, because it is fast, precise, sensitive, and specific.