Report of studies on monoclonal antibodies (MABS) to complement components.

Twenty-five monoclonal antibodies (MABS) to complement components were evaluated according to the ISBT/ICSH protocol by twelve laboratories. Seven detected some form of C3c, but one of them, 174, did not react with EiC3b, although it was positive with 'EC3b' (Fruitstone). 174 may detect some form of enzyme sensitive C3b antigen, but C3a was not evaluated (present on 'EC3b' Fruitstone).

Report of studies on monoclonal anti-IgG antibodies.

Eleven monoclonal anti-IgG antibodies were evaluated by ten laboratories for possible AHG reagent use by the ISBT/ICSH protocol. Three of the anti-IgGs were selected by tests with weak Fya sensitized cells as this represents the best screening test. One of the IgM class anti-IgGs (205) equalled ISBT/ICSH reference reagents (R3P and RIIIM) against weak anti-D, -K and Fya sensitized cells and it reacted with all four subclasses of IgG.

Monoclonal blood group antibodies.

The large volume requirements for high quality AB0 and RhD typing reagents can now be supplied by selected monoclonal antibodies. Superior anti-A and anti-B monoclonal reagents are each prepared from blends of two antibodies to optimise the intensity of agglutination for slide tests and the potency for detection of the weaker sub-groups, including Ax and Bw by tube techniques. Excellent anti-A,B reagents must also be made by blends of at least two antibodies to optimise both A and B reactions, but the need for their continued use is now debatable.

Replicate tests for the detection and correction of errors in anti-human globulin (AHG) tests: optimum conditions and quality control.

Replicate blind AHG tests with weak IgG anti-D sensitised red cells revealed that 32% of workers caused 5 per cent or more false negative errors by using excessive agitation in reading techniques. The common quality control procedure of adding strongly sensitised cells to all negative AHG tests cannot reveal this type of error. Furthermore, strongly sensitised control cells may create an illusion of safety because AHG giving a false negative test with weak antibody in a serum sample may still show a reassuringly strong positive in the control test.