ABSTRACT

Elution is a procedure for recovery of antibody attached to intact, immunoglobulin-coated red blood cells (RBCs) by disrupting the antigen–antibody bonds. The recovered antibody is collected in an inert diluent and is referred to as an eluate. Testing of an eluate may be desired to identify antibody(ies) coating the RBCs of patients with a positive direct antiglobulin test. Many types of elution procedures have been developed and described; however, an acid elution is suitable for antibody recovery in most cases, such as recovery of alloantibodies and warm-reactive autoantibodies. Studies have compared methods such as xylene, chloroform, digitonin acid, dichloromethane, citric acid, and Immucor Elu-Kit II (cold acid elution). The ELU-Kit II has been shown to be quick and effective at eluting a wide range of alloantibodies as well as autoantibodies without the use of hazardous chemicals or costly reagent preparation time that some methods use. It is for these reasons that the ELU-Kit II is a very popular method for the elution of immunoglobulin G (IgG) antibodies.