New technologies for red-cell serology.

Until 1943, blood-grouping tests were performed mainly on glass slides or tiles but, following the description of the antiglobulin test, tube techniques became widespread. With increasing workloads and pressure to be ever more cost-efficient, other 'reaction vessels' such as microplates have been developed for blood-group serological testing. The indirect antiglobulin test has been shown to be the most effective and reliable method for detecting clinically significant antibodies. As a result, this test has been developed, for example by the introduction of enhancement media such as low-ionic-strength saline and polyethylene glycol. However, the problems and inconvenience associated with the labelling and washing of large numbers of tubes were not overcome until the introduction of the solid-phase antiglobulin test and the newer microtubes containing gel or glass microbeads. These techniques are now replacing the conventional tube tests, but they too have their own limitations. There is still no single technique that will detect all clinically significant red-cell antibodies. Therefore, the safe transfusion of red cells that would survive optimally in the recipient depends not on a single test but on a series of tests and procedures, such as correct patient identification, blood-grouping, antibody-screening and compatibility-testing.