Comparative sensitivity of immunoassays for haptens using monomeric and dimeric antibody fragments

Citation
Sd. Grant et al., Comparative sensitivity of immunoassays for haptens using monomeric and dimeric antibody fragments, J AGR FOOD, 47(1), 1999, pp. 340-345
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Agricultural Chemistry","Chemistry & Analysis
Journal title
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN journal
0021-8561 → ACNP
Volume
47
Issue
1
Year of publication
1999
Pages
340 - 345
Database
ISI
SICI code
0021-8561(199901)47:1<340:CSOIFH>2.0.ZU;2-3
Abstract
A single-chain anti-atrazine antibody fragment, scAb (single-chain Fv with a CK domain), was expressed in Escherichia coli, and monomeric and dimeric species were preferentially purified from periplasmic extracts by chromatog raphy upon nickel chelate immunosorbent columns or by immunoaffinity purifi cation using a constant domain (CK) tag. Recombinant monomeric and dimeric antibody fragments, Fab, and intact monoclonal antibodies were compared in assays by competition between free atrazine in solution and (a) immobilized atrazine-bovine serum albumin conjugate (indirect assay) or (b) atrazine-a lkaline phosphatase (direct assay). Recombinant antibody fragments provided a lower detection Limit than either Fab or intact monoclonal antibody in b oth assay formats. Monomeric fragments displayed a sensitivity of detection down to 0.1 ppb, compared to 1.0 ppb for dimeric fragments and the parenta l monoclonal.