[Intralaboratory quality control in non-quantitative enzyme immunoassays of serological markers for various infections].

For intralaboratory quality control (IQC) of non-quantitative techniques, estimation of the sensitivity and specificity of laboratory analysis was introduced using the new control samples (CS)2 and CS3. The estimation of the sensitivity of laboratory analysis uses the control CS2 with a true positive result, the value of which exceeds the critical value of optimal density (OD), but it is, at the same time, rather low (for example, higher than the upper limit of the mean values of ODcrit +/- 3S and lower than 2 x ODcrit). The estimation of the specificity of laboratory analysis employs the control CS3 with a true negative result, whose OD value should be below ODcrit. To enhance the reliability of quality control on the basis of measurements in 20 analytical series, the control limits of scatter in ODcrit , values (mean ODcrit +/- SD) are set, which determines a decision to be taken on the results of analyses. All subsequent ODcrit, values should be within the set limits of ODcrit. Result convergence assessment, control map construction, and current prompt control use a positive CS1 sample; its OD value is linearly dependent on the marker concentration (approximately 0.5 to 1.5 o.u.). The paper describes a procedure for IQC of non-quantitative techniques as three successive stages, by assessing the intra-series convergence of measurements, by estimating the sensitivity and specificity of laboratory analysis, ODcrit, and the inter-series convergence of measurements, and by making a prompt quality control in each analytical series by means of CS1, CS2, and CS3. Recommendations are given on the continuity of IQC on changing the control specimen, the series of a test system.