Selection of a suitable assay to measure the activity of drugs based on released-active forms (RA forms of Abs) is an important step during their investigation. In this study, ELISA was utilized to examine the effect of RA forms of Abs to interferon gamma on the interaction between monoclonal anti-interferon gamma antibodies and human interferon gamma. The data showed that such RA forms of Abs are able to modulate the antibody interaction with interferon gamma, and it was suggested that the observed influence of RA forms of Abs on 'antibody-antigen' interaction could be used to analyze the activity of this kind of drugs.
Keywords: ELISA; antibodies to interferon-gamma; assay development; immunoassay; interferon gamma; released-activity.