The Insulin antiserum was quality control tested using standard immunohistochemical methods. The antiserum demonstrates strongly positive labeling of rat pancreatic beta cells using indirect immunofluorescent and biotin/avidin-HRP techniques. Recommended primary dilutions for these methods are 1/500-1/1000 in PBS/0.3% Triton X-100 - Cy3 Technique and 1/3000-1/5000 in PBS/0.3% Triton X-100 - biotin/avidin-HRP Technique. Immuostaining is completely abolished by soluble pre-adsorption with bovine insulin at 10 µg per mL of diluted antiserum.