A Simple Automated Method for Complement Estimation in a Continuous Flow System

Abstract

The activity of the complement system is routinely evaluated through the quantitation of serum hemolytic activity in presence of sensitized sheep red blood cells (SSRBC). ³ Such measurements do not reflect the activity of each complement component but provide a useful screening test for clinical investigation in various immunologic disorders. However, time consumption is still a practical limitation of this hemolytic technique. Automated methods using continuous flow systems have been described for complement titration (1–4). These methods are based on serial or exponential dilutions of serum with determination of the 50% hemolytic point, and require numerous manipulations for each sample. We are reporting a similar automated procedure for complement titration in which only one dilution of plasma is assayed in the presence of two SSRBC concentrations. This technique provides a simple, accurate and fast estimation of complement values lying between 20% and 120% of normal.