Recognition of a positive MLR within 4 hours using a carrier free electrophoresis system.

Indicator cells--tanned, surface stabilized sheep erythrocytes--were incubated for 1 h in supernatants of 3 h MLCs. Their electrophoretic mobility was measured by an analytical, carrier free electrophoresis system. The change in their mobility compared with an appropriate control was calculated in per cent and correlated with the conventional measured MLR-cpm. The correlation of the two quantities is statistically highly significant (p less than 0.01). Furthermore, the difference of the electrophoretic mobility values of the group of HLA-D-identical and the groups of HLA-D-haploidentical or -different donors is significant beyond the 1% level (p less than 0.0005). Our method enables, therefore recognition of a positive or negative MLC after only 4 h. Typing for HLA-D-determinants seems to be possible. This could be of great importance for histocompatibility testing and organ transplantation.