Heterogeneity of anti-U demonstrable by the use of papain-treated red cells.

When red cells (RBCs) are treated with papain, one form of the U antigen, which we have named UPS (U papain-sensitive), is almost completely removed or denatured. A second form, UPR (U papain-resistant), remains unaltered on the treated RBCs. Tests on 42 examples of anti-U showed that two contained only anti-UPS, 19 contained only -UPR, and 21 contained separable -UPS and -UPR.

Automated detection of red cell antibodies in donor sera using an automated technology.

The evaluation of two automated (AutoGrouper-16C) antibody detection techniques, designed for routine use is reported. Three channels on the instrument were modified for low-ionic-strength or enzyme methods. The incidence of antibody detection was 90.