Abstract: A human sera dilution buffer solution containing the enzyme collagenase is described, for use in preventing false positive indication reactions taking place when specific IgMs are sought in human sera by ELISA capture assays, in which the enzymatic conjugate consists of antibodies bound to ALP with glutaraldehyde.

Abstract: The enzyme alanine aminotransferase (ALT) is colorimetrically determined as the hydrogen peroxide obtained in the pyruvate hydrolysis reaction catalysed by the enzyme pyruvate oxidase which develops a colour read at 550 nm making use of a reagent composition buffered at pH comprised within 7.0 and 7.5 containing L-alanine, ketoglutaric acid, a source of inorganic phosphorous, the enzyme pyruvate oxidase, a system for revealing the hydrogen peroxide and optionally one or more co-factors which interact in the enzymatic reaction catalysed by the enzyme pyruvate oxidase. It is moreover described a method for the determination of the enzyme alanine aminotransferase making use of said reagent composition and of the surface antigen of the hepatitis B virus (HBsAg), by enzyme-immune assay, in the same serum specimen and in the same well of a microtitration plate.