[The advantages of dynamic evaluation of measurement quality in clinical diagnostic laboratory]

The national standard of laboratory quality control is based on a assumption about normal distribution of random error. The data of procedure of quality control get from analyzer Flexor XL during three months period were examined. The distributions of random error were non-Gauss ones in almost half of all examined tests by reason of both abnormal asymmetry and excess. To prevent possible clinical mistakes the actual level of quality is to be evaluated using dynamic values of bias, variation coefficient and o-metrics based on simple consecutive means. The most appropriate time of averaging consisted about 10 days and had no dependencies of type of test. The actual standard cab y easily improved taking into account the discovered advantages and simplicity of proposed approach.

Use of the recombinant nonstructural 3A, 3B, and 3AB proteins of foot-and-mouth disease virus in indirect ELISA for differentiation of vaccinated and infected cattle

Recombinant foot-and-mouth disease virus (FMDV) proteins 3A, 3B, and 3AB were produced by expressing the corresponding genes in Escherichia coli and purified by metal-chelate affinity chromatography. The recombinant proteins were used as antigens in indirect enzyme-linked immunosorbent assay (ELISA) to differentiate between vaccinated and FMD-infected animals. The following parameters were determined: working concentrations of antigens and peroxidase conjugate of cattle anti-IgG, the optimum composition of blocking buffer, and the positive-negative threshold of the reaction. Tests performed with approximately 200 serum samples taken from animals of different immunity states showed that the protocol with protein 3A as the antigen (3A-ELISA) provided the most reliable differentiation. All the newly developed systems proved to outperform the commercial Chekit FMD-3ABC kit in sensitivity, and 3A-ELISA was no less specific.

[Recombinant non-structural 3A, 3B and 3AB proteins of foot-and-mouth disease virus: use for differentiation of vaccinated and infected cattle]

Recombinant proteins 3A, 3B and 3AB were obtained by expression in Escherichia coli and purified by metal-chelate chromatography. The proteins were used as antigens in indirect ELISA to differentiate vaccinated and infected cattle. While testing 200 sera from cattle 3A-ELISA was more sensitive and specific than 3B- and 3AB-ELISA. Compared with "Chekit FMD-3ABC", 3A-ELISA showed the same level of specificity and higher level of sensitivity.