A new reliable test for crossmatching: microplate hydrogel immunoassay technology

OBJECTIVES: To provide a novel assay to detect incomplete antibodies in the crossmatching test. BACKGROUND: There is a requirement in China that both major and minor crossmatch tests are required. Among all methods of crossmatching, the tube anti-human globulin test requires tedious washing steps and is time-consuming, whereas the microcolumn gel immunoassay anti-human globulin test is susceptible to sample quality. METHODS: The process of the microplate hydrogel immunoassay anti-human globulin test involves the use of our patented hydrogel chromatography medium and U-bottom microplates pre-coated with goat anti-human globulin (AHG). A mixture of red blood cells (RBCs) and serum is centrifuged through the hydrogel under precise conditions. In incompatible reactions, the sensitised RBCs are captured by the pre-coated AHG and form a layer over the bottom of the well, whereas in compatible reactions, the unbound RBCs form a button at the bottom of the well. The sensitivity of this new approach and the performance when testing old specimens were evaluated. RESULTS: This approach was more convenient and slightly more sensitive than the tube anti-human globulin test and was superior to the microcolumn gel immunoassay when testing old specimens. CONCLUSION: In general, this assay is suitable for the routine clinical use of crossmatching to detect incomplete antibodies.