Erythrocyte Antibody Screening in Solid-Phase: A Comparison of Two Solid-Phase Microplate Assays with the Indirect Antiglobulin Test in Polyethylene Glycol for the Detection of Irregular Erythrocyte Antibodies

The screening of a serum for irregular erythrocyte antibodies in the indirect antiglobulin test is a well-established technique. We compared the test results of two different solid-phase microplate indirect antiglobulin tests with a liquid-phase indirect antiglobulin test in tubes. Antibody screening with both solid-phase microplate techniques proved to be more sensitive than the liquid-phase indirect antiglobulin test. In addition, a difference in sensitivity between the two solid-phase techniques was observed: prior immobilization of test erythrocytes on the microplate followed by incubation with a serum and detection of sensitization with antihuman IgG-coated detector cells gave better test results than secondary immobilization on the microplate of test erythrocytes sensitized with antibodies and an antihuman globulin serum.