Indirect immunofluorescent staining of mature rat sperm with odorant receptor antibodies
(A) A phase image of a rat sperm isolated from the cauda epididymis demonstrates its anatomical features including head, connecting piece (CP), midpiece (MP), principal piece (PP), and endpiece (EP); 1000×. (B) Indirect immunofluorescent staining with the OD2 antibody (1:200) illuminates the connecting piece and midpiece of mature sperm. The head, principal piece, and endpiece are negative; 1000×. (C) Indirect immunofluorescent confocal microscopy of positively stained rat sperm overlayed on the corresponding phase image reveals intense staining of the connecting piece and diffuse punctate staining along the plasma membrane of the midpiece; Bar = 5 µm. The fluorescent staining pattern (D) is completely blocked when antibody is preadsorbed with pure peptide (E).