A differential pulse polarographic serum protein assay

Human serum and albumin show a differential pulse polarographic band near -0.6 V. For sufficiently dilute solutions (less than 7 micrograms/ml) at pH 7.0, the polarographic response is linearly related to the solution concentration. At pH 12.6 a near-linear response to 70 micrograms/ml is obtained, but sample equilibration time is slow. The polarographic assay for total serum protein using bovine serum albumin (BSA) to generate a standard curve gave a correlation coefficient of 0.89. The cellular constituents of whole blood do not interfere. The correlation with BSA does not hold for protease-digested serum or albumin.