An improved method for the determination of Fc function of immunoglobulins.

Background and Objectives  The Fc function assay of immunoglobulin G is performed to ensure that the biological activity of the molecule is not compromised during purification and storage. The current British Pharmacopoeia (BP) method is cumbersome, time consuming and requires a continuous source of fresh red blood cells. We have modified the technique to improve the convenience, throughput and reproducibility of the assay by using frozen red blood cells, a microtitre plate format and electronic derivative analysis for processing results. Materials and Method  Immunoglobulin G samples were assayed using either the BP Fc function procedure or a new procedure incorporating frozen cells, microtitre format and electronic derivative analysis. Results  The Fc function results demonstrated that there was no significant difference between the BP and the new improved procedure. Conclusion  In this study, we demonstrated that a new Fc function assay incorporating frozen red blood cells, microtitre format and derivative analysis of haemolysis curves has been shown to be comparable to the standard BP procedure. It offers a more convenient and quicker means of performing analysis of Fc function of immunoglobulins.