About quantitative determination of the D-dimer in the blood by immunochromatographic method.

The paper presents the results of the development of a technology for the quantitative determination of D-dimer in blood with an immunochromatographic (LFIA) kit of reagents «LFIA-D-dimer¼ and instrument accounting of the results. Registration and processing of the digitized indicator of the intensity of staining of the LFIA-test strip using the LFIA-analyzer software allows quantifying the D-dimer content in the sample (in ng DDU/ml). The effectiveness of the proposed approach was evaluated on 258 clinical samples examined in the LFIA with visual and instrument accounting of the results, in comparison with the indicators of D-dimer determination in ELISA. The high reproducibility of the digitized LFIA results was shown - the coefficient of variation (CV) for samples in the range of 100-300 ng DDU/ml (near-threshold in relation to pathological values) was 2.5-5.1%; a tendency to increase CV with a further increase in the concentration of D-dimer was traced. A high correlation of the digitized LFIA result with the research data in the ELISA has been established, which makes it possible to recommend the technology for widespread use in urgent medicine.

Immunochromatographic test for differentiation detection of IgM and IgG to SARS-CoV-2.

The study presents the results of the creation and evaluation of the diagnostic characteristics of the rapid immunochromatographic test for the qualitative detection and differentiation of IgM/IgG antibodies to SARS-CoV-2 in human serum, plasma, and whole blood "ИХА-COVID-19-IgM / IgG". Have been tested some samples without antibodies to SARS-CoV-2 and a samples with two and one type of specific antibodies. The coincidence of the results of immunochromatographic analysis with the results of the immunochemiluminescent method was 87.2%. Test kit can be use as the rapid diagnostic test in the context of the COVID-19 pandemic and to assess the immune status of convalescents.