Creatine kinase (CK) is an enzyme which is present in the cells of most organs. The determination of creatine kinase, and particularly of the three isoenzymes from brain (CK-BB), skeletal muscle (CK-MM) and heart muscle (CK-MB) respectively, is currently performed in clinical chemistry laboratories. The brain isoenzyme (CK-BB) is found elevated in serum of patients with certain neurological diseases.
The project consists of the purification of creatine kinase isoenzyme CK-BB from human placenta. The aim is to certify the catalytic activity concentration of creatine kinase in this well characterized purified enzyme preparation. The method used for the assay is that recommended by the International Federation of Clinical Chemistry (IFCC).
The feasibility study could establish that a stable purified enzyme preparation could be produced in lyophilized form. An interlaboratory study was carried out on that preparation with a view to assigning a value to the CK catalytic activity concentration of the reconstituted material. Nine laboratories participated. The agreement between laboratories was judged satisfactory, permitting to propose the preparation for certification with the following value and uncertainty:
CRM 299 (325 +/- 10) U/l.
The report describing the preparation and the certification exercise has been published as report EUR 13886 (1992).
Funding SchemeCSC - Cost-sharing contracts
EN6 3QG Potters Bar