1The National Committee for Clinical Laboratory Standards.Methodcomparison and bias estimation using patient samples.Approvedguideline,NCCLS,EP9-A2,2002.
5Jansen R, Schumann G, Baadenhuijisen H, et al. Trueness verification and traceability assessment of results from commercial systems for measurement of six enzyme activities in serum: an international study in the EC4 framework of the Calibration 2000 project. Clin Chim Acta,2006,368 : 160-167.
6Schumann G, Bonora R, Ceriotti F, et al. IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37℃. International Federation of Clinical Chemistry and Laboratory Medicine. Part 6. Reference procedure for the measurement of catalytic concentration of gammaglutamyltransferase. Clin Chem Lab Med ,2002,40:734-738.
7Diti F. The new European directive on in vitro diagnostics. Clin Chem Lab Med,2003,41:1289-1298.
