Sodium Citrate Buffer, 0.5M, pH 5.0 is a commonly utilized buffer solution, comprising primarily of citric acid and disodium hydrogen phosphate. It is employed in heat-induced epitope retrieval (HIER) to restore the loss of antigenicity in epitopes within formalin-fixed paraffin-embedded tissues. This solution is the preferred choice for most antibodies and can dissolve captisol in animal tumor models.