DETECTION METHOD BASED ON TIME RESOLVED REAL TIME FLUORESCENT ENERGY TRANSFER (TR-FRET)

摘要

There is provided a method for detecting the presence of a diagnostic moiety indicative of exposure to an infectious organism in a biological sample taken from a human or animal, said method comprising; a)adding to said sample a first fluorescently labelled reagent which binds a first binding partner, and a second fluorescently labelled reagent which binds to a second binding partner, wherein the diagnostic moiety binds to at least one of the binding partners in competition to either or both of the first or second fluorescently labelled reagents, or wherein the diagnostic moiety binds to at least one of the fluorescently labelled reagents in competition to its binding partner, wherein a label on one of the first or second fluorescently labelled reagents acts as a fluorescent energy donor compound and wherein the other of the first or second fluorescently labelled reagent acts as a fluorescent energy acceptor compound which is able to accept fluorescent energy from said donor compound; b)concurrently or separately adding to the sample the first and second binding reagents; c)exciting the fluorescent energy donor compound by illuminating with light of a wavelength which is absorbed by said fluorescent energy donor compound; d)measuring fluorescent signal emitted by said fluorescent energy acceptor compound as a result of its absorption of the fluorescent energy from the donor compound after a time delay; and e)relating the results to the presence or absence of diagnostic moiety in said sample, wherein a reduction in the fluorescent signal measured in step (d) is indicative of the presence of diagnostic moiety in the sample; wherein the first and second binding partners are identical or are associated in some way such that, when the first and second labelled reagents are bound to their respective binding partners, the donor compound and acceptor compound are in sufficient proximity that fluorescent energy transfer can take place after step (c) has been carried out.