Figure 1: Protein location of CNP/NPR-B in human sperm. (a) Immunolocalization of CNP/NPR-B in human sperm. FITC-conjugated secondary antibodies were used for the detection of CNP/NPR-B. DIC images were acquired in parallel and served as the control for sperm morphology. The fluorescence image was merged with the DIC image to show the exact location of the fluorescence. Arrowheads indicate the location of CNP/NPR-B in human sperm. Indirect immunofluorescence ×600. (b) Western Blotting analysis of NPR-B in human testis and human sperm. CNP: C-type natriuretic peptide; NPR-B: natriuretic peptide receptor-B; FITC: fluorescein isothiocyanate; GAPDH: glyceraldehyde-3-phosphate dehydrogenase.