Regularities of interactions in immunochromatographic test systems: Finding the weakest links to improve sensitivity

Abstract

Immunochromatographic test systems (ICTSs) are widely used for various practical needs due to their simple application and rapid results. However, the rapid interactions of reagents when moving along the test strip and the direct registration of the formed complexes by the intrinsic properties of the label limit the detection limits for such test systems, preventing their effective use for a number of new analytes. The report presents an analysis of approaches that ensure highly sensitive ICTSs based on an assessment of the factors limiting the minimal detected concentrations of target compounds. The developed mathematical models of the formation of detectable complexes for different types of ICTSs are presented. It is shown that the immunoreagents used, depending on parameters of their interaction, can be fast or slow within the framework of ICTSs, which affects the detection limit management. Experimentally confirmed methods for varying ICTSs sensitivity are considered, based on reagents' pre-incubation, transfer of heterogeneous reactions into the moving liquid, displacement of binding zones, changes in velocity and geometry of the flow, and the sequence of reagents' introduction. Alternative modulators of the detection limit, such as enhancement of the recorded signal using new labels, label complexes, and additional chemical reactions, are characterized. The use of ICTSs combined with isothermal amplifications and amplification-free tools for the detection of specific oligonucleotides is considered. The developed sensitive ICTSs for priority pathogenic contaminants of food products, based on the proposed approaches, are demonstrated.
The work is financially supported by the Russian Science Foundation (grant 23-46-10011).

Speaker

Anatoly V. Zherdev
A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Acad. Sci.
Russia

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