Premium
Human interferon‐γ quantified via a sensitive one‐site monoclonal antibody in a sandwich ELISA
Author(s) -
Berg KURT
Publication year - 1994
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1699-0463.1994.tb04840.x
Subject(s) - conjugate , monoclonal antibody , chemistry , antibody , interferon , microbiology and biotechnology , monoclonal , virology , chromatography , immunology , biology , mathematical analysis , mathematics
A new, specific and sensitive one‐site ELISA for precise quantification of human interferon‐gamma (HuIFN‐γ) at low levels in 50% human serum samples has been developed. The assay is based on the assumption that biologically active HuIFN‐γ is present exclusively as a dimer. Thus, in contrast to previous reports, the ELISA is based on a single monoclonal antibody (MAb) which is used in two ways: as “catching” antibody and as HRPO‐labelled conjugate. The sensitivity could be improved five‐fold by addition of (NH 4 ) 2 SO 4 to the conjugate solution; the lowest detectable amount of HuIFN‐γ is <0.5 u/ml. Non‐specific interactions were not seen in interferon samples taken from cultures, or samples diluted in ordinary media or 1% BSA. However, >30% of the (serum) samples gave non‐specific false‐positive results when the method was applied to samples containing 50–100% human serum from different donors. The false signals were related to the donors but could ‐ at the expense of the sensitivity which was reduced to 1 u/ml ‐ be abolished by PEG treatment of the (donor) serum samples.