ABSTRACT
In radial partition immunoassay, radial chromatography is used for performing an immunoassay. We describe the application of this technology to the measurement of digoxin in serum by enzyme immunoassay, with the entire testing procedure carried out on glass-fiber filter paper. A sample is applied to a small central area of the filter paper, where it reacts with the antibody to digoxin immobilized there. Subsequently, enzyme-labeled digoxin is applied to react with remaining antibody sites. After incubation, substrate for the enzyme is applied to the center of the reaction area and washes out any unbound label to the periphery of the paper. This step also initiates the enzyme reaction, which is quantified by front-surface fluorescence. A microprocessor-controlled automated instrument has been developed to process the filter paper matrix through the above sequence, and calculate the final result. Total testing time for digoxin is less than 7 min.
Subject(s)
Digoxin/blood , Immunoassay/methods , Antibodies , Antigen-Antibody Complex , Chromatography/methods , Cross Reactions , Digoxin/immunology , Humans , Immunoassay/instrumentation , Immunoenzyme Techniques , Microcomputers , Radioimmunoassay , Time FactorsABSTRACT
We tested the Centri-Sep filter (DADE) for its effectiveness in separating serum from clotted blood samples used for chemical analysis. Although statistical analysis by paired t-test showed differences in results for some analytes with the use of this device as compared with use of no separator or of a serum-decanting device, we concluded from the small bias of the paired means that the new separator device did not interfere with the clinical usefulness of reported values for the analytes studied. The separator is not an effective barrier for long-term storage of serum on its clot; however, we could obtain about 10% more serum with the separator than with decanting devices.
