Syntex (u.s.a.) Inc.

Richard P Watts

John W Vorpahl

Mary C Ericson

Wylie I Lee

Edwin F Ullman

Hrair Kirakossian

Chiu C Chang

Hriar Kirakossian

A method for carrying out an immunoassay for an analyte in which a sample suspected of containing an analyte and reagents useful for detecting the analyte of interest are combined in an aqueous medium, wherein one of the reagents includes a support and one includes a label, the improvement comprising employing as the reagents a first and second conjugate, each comprised of a specific binding pair (sbp) member bound to a small molecule wherein the small molecules of each conjugate are different.

Compositions useful in heterogeneous immunoassays

A method for carrying out a binding assay is described wherein a member of a specific binding pair (sbp) and a sample are combined with a matrix of non-porous beads in a liquid medium under conditions such that the beads bind to the sbp member. The liquid medium is removed from the beads by aspiration using an aspiration tube having one or more orifices each of a diameter smaller than the minimum diameter of the smallest bead thereby allowing removal of the liquid medium while prohibiting aspiration of the beads.

Heterogeneous binding assays

An apparatus and method are described for defining a small interrogation volume in a liquid sample suspected of containing an analyte. The apparatus and method utilize a dual optical fiber probe constructed with the ends of the optical fibers at the liquid-fiber interface spatially oriented such that the intersection of their longitudinal axes forms an included angle ranging from about 40.degree. to 140.degree.. By appropriate choice of the numerical aperture and core diameter of the optical fibers and the separation distance between the longitudinal axes of the optical fibers at the liquid-fiber interface, a finite interrogation volume of predetermined size and independent of the total liquid sample volume can be defined. The apparatus and method substantially reduce background interference with corresponding increase in assay sensitivity.

Method for detection of fluorescence or light scatter

An apparatus and method are described for defining a small interrogation volume in a liquid sample suspected of containing an analyte. The apparatus and method utilize a dual optical fiber probe constructed with the ends of the optical fibers at the liquid/fiber interface spatially oriented such that the intersection of their longitudinal axes forms an included angle ranging from about 40.degree. to 140.degree.. By appropriate choice of the numerical aperture and core diameter of the optical fibers and the separation distance between the longitudinal axes of the optical fibers at the liquid/fiber interface, a finite interrogation volume of predetermined size and independent of the total liquid sample volume can be defined. The apparatus and method substantially reduce background interference with corresponding increase in assay sensitivity.

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San Mateo, CA, United States of America

Richard P Watts