fluorescein-thiocarbamylethylenediamine and Acquired-Immunodeficiency-Syndrome

Attempts to increase the sensitivity of fluorescein-based fluorescence immunoassays by using multiple labelling have generally been unsuccessful because of concentration quenching. We have labelled antibodies to human immunoglobulin G with multiple fluorescein fluorophores attached by means of a disulphide linkage: this linkage can be rapidly and easily broken by treatment with dithiothreitol, allowing fluorescein to be released from the antibody and measured in free solution. Application of this technique to a fluorescence labelled immunosorbent assay for antibodies to the human immunodeficiency virus gave an approximately 20-fold increase in signal compared with an equivalent assay using fluorescein isothiocyanate.

Topics: Acquired Immunodeficiency Syndrome; Fluoresceins; Fluoroimmunoassay; HIV Antibodies; HIV Antigens; Humans; Immunoglobulin G