Evidence that the low-incidence red cell antigens Rla and Lsa are identical.

: Testing of Ls(a+) and Rl(a+) red cells with numerous antisera containing antibodies to low-incidence antigens indicated that these antigens are identical. This conclusion was confirmed by adsorption and elution tests, and supported by immunoblotting of Ls(a+) and Rl(a+) cells with antibodies to glycophorin C and glycophorin D.