DEVELOPMENT OF A LIPOSOME IMMUNOSORBENT-ASSAY FOR HUMAN INTERFERON-GAMMA

A novel and sensitive liposome immunosorbent assay (LISA) for IFN-gamm a is described. Biotinylated liposomes with encapsulated carboxyfluore scein comprise a universal label for immunoassays. Stability of the li posomes is proven to be adequate for long-term storage, without loss o f encapsulated marker. Sensitivity of the LISA of 6 x 10(-12) M is com parable to the best colorimetric immunoassays for IFN-gamma, and the l inear detection range (6-2400 x 10(-12) M) exceeds the colorimetric ra nge. Analysis of biological samples with the LISA showed no interferen ce on the liposomes from potential disturbing factors in either plasma or blood cell culture supernatants.