Abstract
We have developed a one-step, homogeneous noncompetitive immunoassay for
small analytes using recombinant antibodies and morphine as the model
analyte. A highly specific antibody against the immune complex (IC)
formed between an anti-morphine antibody and morphine was selected from a
naïve scFv phage display library. The in vitro phage library selection
procedure avoids the difficulties associated with the production of
anti-IC antibodies by animal immunization. The anti-morphine and the
anti-IC antibodies were labeled with a pair of fluorescence resonance
energy transfer (FRET) fluorophores. In the FRET assay the labeled
antibodies were incubated with saliva samples spiked with morphine,
codeine, or heroin. Within 2 min, 5 ng/mL morphine, which is clearly
under the recommended cutoff level, was detected without
cross-reactivity to codeine or heroin. This assay principle is also
widely applicable to other small analytes.
Original language | English |
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Pages (from-to) | 2637 - 2642 |
Number of pages | 6 |
Journal | Analytical Chemistry |
Volume | 77 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- immunoassay
- antibodies
- detection
- drug detection
- drug abuse