MODERN METHODS OF IMMUNOENZYME ANALYSIS IN MEDICINE: THEORETICAL FOUNDATIONS, APPLICATION AND PROSPECTS (Literature Review)

MODERN METHODS OF IMMUNOENZYME ANALYSIS IN MEDICINE: THEORETICAL FOUNDATIONS, APPLICATION AND PROSPECTS (Literature Review) Turakulov Zhavlon Sodik ugli Assistant of the Department of Clinical Laboratory Diagnostics and with a course in clinical laboratory diagnostics PGF, Samarkand State Medical University, 18 Amir Temur Street, Samarkand, Uzbekistan. Tel: +998 66 233 0841 Email: sammi@sammi.uz Rabbimova Dilbar Jaloliddinovna Cadet of the Department of Clinical Laboratory Diagnostics and with a course in clinical laboratory diagnostics PGF, Samarkand State Medical University, 18 Amir Temur Street, Samarkand, Uzbekistan. Tel: +998 66 233 0841 Email: sammi@sammi.uz https://doi.org/10.5281/zenodo.18282547 Abstract: Enzyme-linked immunosorbent assay (ELISA) is one of the most in-demand immunochemical methods in modern biomedical and toxicological practice, allowing for the qualitative and quantitative determination of medicinal and narcotic substances in biological fluids. Unlike instrumental analytical methods, ELISA is characterized by high sensitivity and specificity, minimal sample preparation, and the possibility of highly productive screening. The article examines the theoretical foundations of enzyme-linked immunosorbent assay (ELISA), the classification of heterogeneous and homogeneous ELISA methods, and the characteristics of competitive and non-competitive analysis forms. Particular attention is paid to the role of enzyme tags, antibodies (poliklonal and monoclonal), as well as the stages of their production and purification. Modern trends in the development of ELISA technologies, areas of clinical and chemical-toxicological application, including the determination of drugs and their metabolites in live and post-mortem samples, have been analyzed. The factors influencing the accuracy and reliability of the results, such as the matrix effects of biological fluids, enzyme activity inhibition, and cross-reactivity, were considered separately. A conclusion was made about the high diagnostic value of ELISA, provided that the analytical requirements are met and positive results are confirmed by alternative analysis methods. Key words: enzyme-linked immunosorbent assay, ELISA, immunodiagnostics, medicinal substances, biological fluids, antibodies, enzyme tags.