Abstract: A method for treatment of animal blood to simulate human blood for use as a reference standard for automated biological testing instruments wherein the enzyme activities are reduced by base-acid treatment of the serum or plasma from animals and which may include one or more additional treatments, such as decolorizing with an oxidant, removal of inorganic phosphate with an anion exchange resin, reduction of other electrolyte levels by treatment with a mixed bed ion exchange resin, reduction of glucose by treatment with glucose oxidase and the blending of processed animal sera to achieve constituent levels corresponding with human blood serum, including lyophilization of the serum product.