Test cells for use with anti-IgG sub-typing antisera in the antiglobulin test

The preparation of test cells coated with specific IgG of known subclass is described. Such cells are required in the standardization of IgG subtyping reagents. At present, these test cells usually are prepared by coating cells with IgG myeloma paraproteins. However, these paraproteins may not be generally available and an alternative method is presented using more readily obtainable materials. Quantification of cell-bound IgG showed that the subclass did not affect the sensitivity of the antiglobulin test when using broad-spectrum anti-IgG and that the test cells produced had an optimal IgG coating. Reactions with subclass-specific antisera were however, considerably weaker that those obtained with broad-spectrum anti-IgG. A modified spin-layering technique for use with subclass-specific antisera is described.