Expression and distribution of phospholipase Cζ (PLCζ) protein in human sperm. (A) Immunoblot analysis of PLCζ protein in human sperm. Sperm cells (25,000 per lane) were analyzed by 9% SDS-PAGE, proteins were electrophoretically transferred, and the blot membrane was incubated either with affinity-purified, anti-PLCζ polyclonal antibody (V-37; 1:7,500 dilution; left panel) or with anti-β-actin monoclonal antibody (1:2,500 dilution; right panel). (B) Representative confocal microscope images of PLCζ immunofluorescence in human sperm after fixing and immunostaining with anti-PLCζ polyclonal antibody (V-37; 1:1,000 dilution) showing that the native PLCζ in this IVF patient localizes to the equatorial and acrosomal region of the sperm head.