FC receptor for IgM: factors influencing detection on human T lymphocytes.

This paper is concerned with technical standardization in detecting Fc-IgM receptors on human T lymphocytes. We have investigated a number of factors of critical importance in obtaining easily reproducible and reliable estimates of the numbers of TM cells among human peripheral T lymphocytes. A point of major importance is optimal coating of erythrocytes by IgM molecules. For this condition to be met, particular attention is required when erythrocytes from animals other than the one used for obtaining antiserum are used to prepare EA-IgM. Determination of the agglutinating titer of IgM preparation is useful in determing optimal sensitizing dilutions. Full expression of Fc receptors is favoured when human cord serum is added to the medium. The influence of incubation period of EA-lymphocytes mixtures on TM counts has also been investigated.