Study of affinity interactions of diagnostic antigen-antibody and antigen-aptamer molecules by selected immunoanalytical methods

This study aimed to confirm the use of aptamer molecules for detecting biologically active proteins (biomarkers) and compare them with antibodies. Aptamer-biomarker and antibody-biomarker interactions were examined using various immunoanalytical methods to assess specificity and explore aptamers as alternatives to antibodies. Human epididymis protein 4 (HE4), commonly expressed in ovarian malignancy, was the model biomarker. Anti-HE4 IgG antibodies and biotin-conjugated aptamer molecules were used for testing. Methods included immunoblotting/dot-blotting with colourimetric/chemiluminescent detection, polyacrylamide gel electrophoresis (SDS-PAGE), and bioconjugation techniques.