Alkaline phosphatase (AP) is an enzyme found in particular in the cells which are responsible for the bone formation (osteoblasts). This enzyme is involved in the process of calcification of the bone. The catalytic activity of the enzyme is measured in serum primarily for the diagnosis of bone disease. It is an adjunct for the detection of bone cancer.
The project involves the purification of alkaline phosphatase extracted from porcine kidney, its stabilization in an albumin matrix and the production of a batch of samples for certification. The catalytic activity concentration of AP in the partly purified preparation will be certified according to the method of the International Federation of Clinical Chemistry (IFCC).
The project was completed in 1988. A stable preparation of partly purified alkaline phosphatase was produced. The material is in lyophilized form. A strict procedure for reconstitution of the lyophilized enzyme preparation was specified to avoid time -and temperature -dependent increase of activity of the reconstituted AP preparation. The catalytic concentration activity of the reconstituted material was measured by 14 laboratories according to the IFCC method. The certified value and uncertainty were established as:
CRM 371 (254 +/- 6) U/l.
Details on the preparation of the partly purified enzyme and on the results of the certification campaign are presented in the report EUR 11774 (1988).
Funding SchemeCSC - Cost-sharing contracts
EN6 3QG Potters Bar
W12 ONN London