5. CALlERATION BY REFERENCE ENZYME MATERIALs
For details refer to the corresponding section and references
in the ECCLS standard for CK, above.
6. REFERENCE VALUES Provided this standard is followed the
variability of reference values should depend only on the in–
dividuals selected in different studies. Therefore, the popu–
lation selection criteria, measurement temperature and, if
temperature conversion factors have been used, detailed
description of the ca- libration procedure and calibration
material should be given to allow comparison.
7. WITHIN-LABORATORY IMPRECISION
This should be similar to that described for the IFCC ALAT
Reference Method (2).
8. REAGENT SPECIFICATIONS
Refer to the IFCC ALAT Reference Method (2).
9. RELATIONSHIP TO OTHER METHOD PRINCIPLEs
Instruments with specific instrument-dependent methods which
do not fall within the tolerance limits of this ECCLS stan–
dard Method may nevertheless be able to produce numerically
equivalent results by a calibration process. In such cases
the manufacturer should document that the methods fulfill the
performance criteria given in 2.1 of these ECCLS Standards.
The validatian of calibration of enzyme methods is discussed
in ECCLS Reference Enzyme Materials, Draft 2, 1987 (9). It is
not possible to relate methods without pyridoxal-5'-phosphate
activation to the ECCLS standards for ASAT and ALAT.
Klinisk kemi
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Norden 2: supp/, 1990
69
