The intrinsic viscosity of mixed protein systems, including studies of plasma and serum.

Experimental evidence is presented that the intrinsic viscosity of solutions of mixed proteins obeys the additive equation See PDF for Equation. The datum serves to characterize the system, and combined with other analytical techniques and fractionation procedures, enables one to analyze and characterize subfractions. The plasmas and sera of clinically "normal" individuals give intrinsic viscosity values agreeing with calculated values. The intrinsic viscosity values for pathological plasmas and sera in all cases are greater than normal and reflect the augmented levels of those proteins fibrinogen, alpha(2)-globulins, and gamma-globulins occurring in the pathological state. The method is readily adaptable to routine clinical use and furnishes a measure of the departure from normal of protein levels in serum and plasma.