A viscometric method of measuring plasma fibrinogen concentrations.

A technique based on deducing the viscosity of serum from that of plasma was compared with the commonly used Clauss method. The two methods correlated closely (r = 0.914). The reproducibility of the viscometric method was slightly poorer than the Clauss technique at low fibrinogen concentrations, equal to that at medium fibrinogen concentrations, and marginally better at high concentrations. Fibrinogen can therefore be measured reasonably accurately with the viscometric method, and can be recommended as an alternative for laboratories possessing a viscometer.