Immunocytochemistry analysis of CD4 in immersion fixed feline peripheral blood mononuclear cells (PBMCs). Samples were incubated in CD4 polyclonal antibody (Product # PA5-47351) using a dilution of 15 µg/mL for 3 hours at room temperature followed by NorthernLights™ 557-conjugated Anti-Goat IgG Secondary Antibody (red) and counterstained with DAPI (blue). Specific staining was localized to cytoplasm.