A Protein L -Based Immunodiagnostic Approach Utilizing Time-Resolved Forster Resonance Energy Transfer

作者：Hepojoki Satu; Nurmi Visa; Vaheri Antti; Hedman Klaus; Vapalahti Olli; Hepojoki Jussi^*

来源：PLos One, 2014, 9(9): e106432.

DOI：10.1371/journal.pone.0106432

Chelated lanthanides such as europium (Eu) have uniquely long fluorescence emission half-lives permitting their use in time-resolved fluorescence (TRF) assays. In Forster resonance energy transfer (FRET) a donor fluorophore transfers its emission energy to an acceptor fluorophore if in sufficiently close proximity. The use of time-resolved (TR) FRET minimizes the autofluorescence of molecules present in biological samples. In this report, we describe a homogenous immunoassay prototype utilizing TR-FRET for detection of antibodies in solution. The assay is based on labeled protein L, a bacterial protein that binds to immunoglobulin (Ig) light chain, and labeled antigen, which upon association with the same Ig molecule produce a TR-FRET active complex. We show that the approach is functional and can be utilized for both mono- and polyvalent antigens. We also compare the assay performance to that of another homogenous TR-FRET immunoassay reported earlier. This novel assay may have wide utility in infectious disease point-of-care diagnostics.

• 出版日期2014-9-2