E. Gerlo et F. Gorus, CALIBRATION OF ION-EXCHANGE HPLC MEASUREMENTS OF GLYCOHEMOGLOBIN - EFFECT ON INTERASSAY PRECISION, Clinical chemistry, 43(12), 1997, pp. 2353-2357
To investigate the effect of calibration with lyophilized calibrators
on the interassay precision of glycohemoglobin (glyHb) measurements, w
e used an ion-exchange HPLC system equipped with a Pharmacia Mono S(R)
HR 5/5 column. Calibration of analytical runs substantially increased
interassay variation (CV), from 1.7% to 4.4% and from 0.9% to 3.2% fo
r control samples with low (6.5%) and high (14%) glyHb percentages, re
spectively. Standardization of glyHb results, though essential for int
erlaboratory comparisons, should not be done at the expense of assay p
recision, as may occur with thoughtless use of lyophilized calibrators
. We therefore recommend the use of carefully determined conversion fa
ctors for standardization of glyHb results obtained with ion-exchange
HPLC systems that are capable of excellent long-term interassay precis
ion.