Immunofluorescence analysis of Connexin 37 (Cx37) was performed on sections of adult mouse heart. Tissue sections on slides were probed for 24 h at 4°C in a humidified chamber with rabbit polyclonal anti-Cx37 (Product # 40-4200) at an antibody concentration of 1-2 µg/mL diluted in 50 mM Tris-HCl, pH 7.4, containing 1.5% NaCl, 0.3% Triton X-100 (TBST) and 4% normal goat serum. After overnight incubation, sections were washed extensively for 1 h in TBST, and detection of primary antibody was performed for 1.5 h at room temperature with AlexaFluor-488-conjugated donkey anti-rabbit diluted 1:600 in TBST. Sections were then washed in TBST, then in TBS (without triton) and then coversliped with anti-fade medium. Images were taken on a Zeiss 710 confocal microscope at x40 objective magnification, and show immunofluorescence labelling of Cx37 distributed at presumptive gap junctions along a blood vessel in adult mouse heart. Data courtesy of Dr. James Nagy's lab.