Fluorescein Isothiocyanate-Labeled Protein G as an Affinity Ligand in Affinity/Immunocapillary Electrophoresis with Fluorescence Detection

verfasst von
Oscar Werner Relf, Ruth Freitag, Ralf Lausch, Thomas Scheper
Abstract

Antibodies from human sera (h-IgG) were tagged with a fluorescent dye (fluorescein isothiocyanate, FITC) through the affinity reaction of FITC-labeled protein G with the Fc fragment of the antibodies. The complexes were quantified by capillary zone electrophoresis (CZE) within 1 min, i.e., fast enough to prevent their dissociation during the measurement. Conditions for the affinity reaction and the CZE analysis could thus be optimized independently. When an FITC-labeled protein G concentration of 10−6 mol/L was used, h-IgG concentrations between 10−6 and 10−9 mol/L were reproducibly quantified (STD < 2%), using an LIF detector. A correlation coefficient, r2, of 0.9988 was established between the peak height and the IgG concentration. Alternatively, h–IgG containing serum samples and the FITC-labeled protein G were simply injected into the CE capillary in consecutive zones, followed by the application of the electrical field. Within 2 min, the affinity complexes were resolved and the IgG content of the serum quantified (r2 = 0.9986). The injection sequence was of no consequence. The measurements agreed well with those found in a single radial immunodiffusion (SRID) assay. In addition FITC-labeled protein G-tagged anti-h-IgG1 antibodies were used to detect the specific antigen of the involved antibody, namely, h-IgG1, in human sera.

Externe Organisation(en)
Westfälische Wilhelms-Universität Münster (WWU)
Typ
Artikel
Journal
Analytical chemistry
Band
66
Seiten
4027-4033
Anzahl der Seiten
7
ISSN
0003-2700
Publikationsdatum
15.11.1994
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Analytische Chemie
Elektronische Version(en)
https://doi.org/10.1021/ac00094a027 (Zugang: Unbekannt)