New refractometric methods for the determination of total proteins in serum and in urine.

New, precise, physical methods for the determination of total protein in serum or plasma and in urine are described. They are based upon the refractometric determination of total solids in these fluids before and after protein has been removed by coagulation and, in ordinary use, they require no special standardization or calibration. The urine method is applicable primarily to protein concentrations above 100 mg./100 ml. A by-product of the urine method is the direct and simple determination of the nonprotein specific gravity of proteinuric urine.