[Evaluation according to the NCCLS protocol of the Kodak-Ektachem procedure applied to the estimation of glucose and urea in plasma (author's transl)].

The study carried out consists of evaluating the results obtained for estimation of glucose and urea with a procedure the originality of which resides mainly in the use of preconditioned reagents, in the dry form, laid out on a support where the colour develops, proceeding to a reading by reflectometry and linearise the response by a procedure of calculation carried out by a microprocessor. The evaluation of the results obtained with the Kodak-Ektachem prototype for estimations of glucose and urea in the plasma was carried out according to the NCCLS protocol in the field of a coordinated European study. The imprecision was estimated at several levels of concentration after a study of intraserial and day to day reproducibility with and without contamination correction, the variation coefficients obtained from day to day are less than 3% when the concentrations of glucose and urea are higher than 5 mmol.l, the lower concentrations lead to less precision. No contamination was demonstrated. The inaccuracy is evaluated by comparison of the results supplied by the testing apparatus with those obtained by techniques chosen as reference. (Direct hexokinase with deduction of a blank sample and final reading at 340 nm for glucose, a colorimetric technique using monoxime diacetyl adapted to continuous flow for urea). The correlations between these methods are good : (mmol.l1) glucose : (EKTA) = 0.07 + 1,025 (HK); r = 0,993. Urea : (EKTA) = = 0,498 + 1,046 (DAM); r = 0,995. Further studies on the influence of proteins and a few physiological and drug substances liable to interfere have shown that a routine use in the laboratory may be considered favourably.