Lack of specificity of M-20 and C-20 antibodies when used for immunohistochemistry. To obtain EPOR-knockout (EPOR-/-) mouse embryos, timed matings were performed with heterozygous EPOR+/- mice.21 EPOR+/+ and EPOR-/- embryos (determined by yolk sac DNA polymerase chain reaction genotyping21 ) were recovered at day 12.5 for histology of the complete embryo and at day 13.5 for liver tissue. EPOR-/- embryos and EPOR+/+ embryos from wild-type littermates stained with M-20 (A,D). EPOR-/- and EPOR+/+ embryos stained with M-20 preincubated with a 5-fold excess of M-20 peptide (B,E). Rabbit IgG control antibody (C,F). UT-7/Epo, 769-P, and MCF-7 cell lines stained with C-20 (G,J,M). C-20 preincubated with a 5-fold excess of C-20p (H,K,N). Rabbit IgG control antibody (I,L,O).
