Document Detail


Capillary electrophoresis coupled with laser-induced fluorescence polarization as a hybrid approach to ultrasensitive immunoassays.
MedLine Citation:
PMID:  10486766     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Immunoassays using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) is a powerful approach to the determination of trace amounts of analytes in a complex biological matrix. However, its applicability is limited by the requirement that the free and bound tracer (fluorescently labeled compound) be resolved for their identification and quantitation. Here we show that replacing LIF with laser-induced fluorescence polarization (LIFP) permits ultrasensitive immunoassays to be performed with or without the separation of the free and bound tracer. A binding system involving cyclosporin A (CyA) and monoclonal antibody to CyA was chosen to demonstrate both homogeneous and heterogeneous immunoassay approaches. In the homogeneous scheme where the free and bound tracer were not separated, the fluorescence polarization of the mixture was a quantitative measure of the antibody-bound tracer. The concentration and mass detection limits for CyA using the homogeneous competitive assay were found to be 1 nM and 1 amol (10(-18) mol), respectively. The heterogeneous assay involved a nearly baseline separation of the free and bound tracer using CE with a phosphate running buffer of pH 7.0. The complex of the tracer with the antibody had a fluorescence polarization of approximately 0.24 whereas the free tracer had negligible polarization. The fluorescence polarization was independent of analyte concentration, and the fluorescence intensity of either the free or bound tracer was used for quantitation. Results from both assays suggest that the CE-LIFP approaches may have a wider application than the immunoassays based on either CE-LIF or fluorescence polarization alone.
Authors:
Q H Wan; X C Le
Related Documents :
3307546 - Correlation between seralyzer reflectance photometer theophylline assay and an emit assay.
12467926 - Development of generic continuous-flow enzyme immunoassay system for analysis of aminog...
8425566 - Damage of tracer erythropoietin results in erroneous estimation of concentration in mou...
1164806 - The use of microfilters as an alternative to centrifugation in radioimmunoassay.
23285976 - Extraction chromatography of aluminium (iii) and mutual separation of aluminium (iii), ...
232706 - Urine analysis of platinum species derived from cis-dichlorodiammineplatinum(ii) by hig...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of chromatography. A     Volume:  853     ISSN:  0021-9673     ISO Abbreviation:  J Chromatogr A     Publication Date:  1999 Aug 
Date Detail:
Created Date:  1999-10-26     Completed Date:  1999-10-26     Revised Date:  2009-01-15    
Medline Journal Info:
Nlm Unique ID:  9318488     Medline TA:  J Chromatogr A     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  555-62     Citation Subset:  IM    
Affiliation:
Department of Public Health Sciences, Faculty of Medicine, University of Alberta, Edmonton, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Antibodies, Monoclonal / immunology
Cyclosporine / analysis*,  immunology
Electrophoresis, Capillary / methods*
Fluorescence Polarization
Fluorescence Polarization Immunoassay / methods*
Humans
Lasers
Chemical
Reg. No./Substance:
0/Antibodies, Monoclonal; 59865-13-3/Cyclosporine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Competitive immunoassay for staphylococcal enterotoxin A using capillary electrophoresis with laser-...
Next Document:  Good & evil in the crusade of care. Social constructions of mental disorders.