Multienzyme control serum (Seraclear-HE) containing human enzymes from established cell lines and other sources. 1: Preparation and properties.

We have developed a new multienzyme control serum, Seraclear-HE, which was designed to function not only as an accuracy and precision control serum but also as an intermethod calibrator for unifying interlaboratory clinical enzyme data in terms of reference method values. Seraclear-HE contains as analytes the following enzymes of human origin only: aspartate aminotransferase (AST, EC 2.6.1.1) and lactate dehydrogenase (LD, EC 1.1.1.27) from erythrocytes; alanine aminotransferase (ALT, EC 2.6.1.2) from a hepatoma cell line; alkaline phosphatase (ALP, EC 3.1.3.1) from an amnion cell line; creatine kinase (CK, EC 2.7.3.2) from an embryo kidney cell line; gamma-glutamyltransferase (GGT, EC 2.3.2.2) from a macrophage cell line; and amylase (AMY, EC 3.2.1.1) from urine and saliva. The seven partly purified enzymes were lyophilized in partially delipidated human serum containing sucrose (50 g/L), pyridoxal 5'-phosphate (30 mmol/L), and other stabilizers. The material is stable for at least 2 years at temperatures < or = 10 degrees C. For two concentrations of this preparation, reference method values (mainly International Federation of Clinical Chemistry and Japan Society of Clinical Chemistry) obtained at both 30 degrees C and 37 degrees C are assigned.