A highly sensitive, immunoassay method for determining the amount of an analyte in a sample containing a known analyte in an unknown concentration is provided. Sample; a polypeptide-labeled analog of the analyte, an antibody specific for said analyte, a polypeptide partner capable of non-covalently binding with the polypeptide-labeled analyte to form a complex having catalytic activity, and a substrate capable of being converted to a reporter molecule by the catalytic activity of said complex ar...

A method for stabilizing analytes with antibodies and antibody fragments comprises dissolving the analyte in a liquid to form a solution, adding analyte-specific antibodies, fragments of such antibodies, or both to the solution, heating the solution, and then cooling and filtering the solution. The filtered solution may be diluted in a suitable matrix.

In order to detect analytes with an immunological method by incubation with receptors and analysis of the complexes formed, a mixture of at least two monoclonal antibodies which are specifically bindable to the analyte and whose cross-reactivities are different are used for at least one of the receptors.

A method for conferring or increasing the antigenicity of a disulfide-crosslinked protein by treating the protein with an oxidizing agent, such as periodate, having an oxidation potential sufficient to cleave disulfide linkages. Excess oxidizing agent is then inactivated by addition of a reducing agent. The resulting protein exhibits an increase in its ability to be bound by select antibodies, particularly monoclonal antibodies directed to linear peptide epitopes in the protein.

A method for determining the presence of an analyte in a fluid is described along with various components of an apparatus specifically designed to carry out the method. The method involves taking a reflectance reading from one surface of an inert porous matrix impregnated with a reagent that will interact with the analyte to produce a light-absorbing reaction product when the fluid being analyzed is applied to another surface and migrates through the matrix to the surface being read. Reflectance...

Chemical sensors for detecting analytes in fluids comprise first and second conductive elements (e.g., electrical leads) electrically coupled to and separated by a chemically sensitive resistor which provides an electrical path between the conductive elements. The resistor comprises a plurality of alternating nonconductive regions (comprising a nonconductive organic polymer) and conductive regions (comprising a conductive material) transverse to the electrical path. The resistor provides a diffe...

The present invention discloses a method for transdermal extraction and measurement of analytes in an individual's body comprising the steps of permeabilizing the skin by electroporation in the presence of liposomes comprising negatively charged lipids, and extracting the extracellular fluid through the permeabilized skin by using suction. Analytes may be quantitated in the extracted extracellular fluid.

Compositions and methods for assaying analytes, preferably, small molecule analytes. Assay methods that employ, in place of antibodies or molecules that bind to target analytes or substrates, modified enzymes, called substrate trapping enzymes. These modified enzymes retain binding affinity or have enhanced binding affinity for a target substrate or analyte, but have attenuated catalytic activity with respect to that substrate or analyte. The modified enzymes are also provided. In particular, a ...

Methods and devices are provided for measuring the concentration of target chemical analytes present in a biological system. Device configuration and/or measurement techniques are employed in order to reduce the effect of interfering species on sensor sensitivity. One important application of the invention involves a method and device for monitoring blood glucose values.

An apparatus includes an enclosed chamber in which a motor-driven cylinder is mounted for rotation about a horizontal axis. The lower half of the cylinder is disposed in a trough. A blot can be attached, analyte side outward, to the surface of the cylinder, and the cylinder is then rotated to carry the blot through a succession of treatment liquids, with which the trough is charged. Each liquid is discharged from the through before the next liquid is supplied. The liquid in the through can be ma...