Abbott Laboratories Corporation

Martin Wong

John M Brackett

John M Ramp

David M Finley

Stephen D Stroupe

Peter J Tarcha

Mark R Shaffar

James J Donovan

Gary L Boltinghouse, Jr

The present invention provides a method of improving the sensitivity and accuracy of a lead assay. The method enhances the recovery of lead during isolation of the lead from interfering compounds by maintaining the lead in a sample solution and making the recovered lead available for detection by the assay. An enhancing reagent complexes with the lead isolated in the sample solution. The enhancer includes a chelator having a lead equilibrium binding constant in the range of about 4 log K to about 13 log K. A kit for performing such a lead assay is also provided.

Method and compositions for enhancing aminolevulinic acid dehydratase

Detection of lead present in a sample, comprising the steps of: (a) adding a lead recovery agent to an assay solution containing lead from the sample; (b) adding to the assay solution a disulfide enzyme which is inhibited in the presence of lead; and (c) correlating the activity of the disulfide enzyme to the amount of lead in the sample. The lead recovery agent enhances the sensitivity and accuracy of the assay such that the assay can be readily automated for detection of lead in whole blood using commercially available automation systems.

Automated lead assay

A method and kit for simplifying and improving the sensitivity and accuracy of a lead assay for a sample solution suspected of containing lead determines the extent of a reaction between a substrate and a disulfide enzyme in the presence of an activating reagent which contains a water-soluble tertiary phosphine reagent so as to increase the activity of the disulfide enzyme for reaction with the substrate. For a colorimetric determination of the enzyme activity a chromophore is formed upon reaction with a selected component of the sample solution in the presence of a colorimetric enhancing reagent. The colorimetric enhancing reagent contains a metal ion such as cupric ion or ferric ion which is soluble in the sample solution. The extent of the chromophore formation is then photometrically determined.

Lead detection method and reggents utilizing aminolevulinic acid

An indicator reagent, assay method and test kit for determining the presence or amount of an analyte in a test sample, in which the indicator reagent is formed by attaching an organic polymer latex particle, preferably a colored particle, to a specific binding member. The specific binding member can be adsorbed onto or covalently bound to the organic polymer latex particles. The organic polymer latex particles are readily detected by direct visual observation or can be detected and/or measured by appropriate instrumentation.

Indicator reagents, diagnostic assays and test kits employing organic

A dispersion of a uniformly sized population of multilamellar lipid vesicles (liposomes) encapsulating an aqueous liquid is prepared by forming a dried film of lipids on the walls of a vessel, contacting the film with an aqueous liquid in the presence of spherical contact masses such as glass beads and agitating. The liposomes have mean diameters in the range of about 150 to about 3000 nanometers and the contact masses have mean diameters of about 50 to 3,000 microns. The aqueous liquid encapsulated may contain enzymes, drugs or marker substances such as colorimetric or fluorescent dyes. A member of a immunological binding pair may be associated with the surfaces of the liposomes for carrying out immunoassays. This method allows for the use of small quantities of marker and lipid, leaves no residual solvents, allows for contact with only glass surfaces and involves no transfer of liposome preparations from lipid film drying vessels to sizing apparatus.

Preparation of uniformly sized liposomes encapsulating an aqueous liquid

The present invention provides novel methods for generating aqueous liquid encapsulating multi-lamellar lipid vesicles (liposomes) wherein one or more lipids, or lipid conjugates, and an aqueous liquid to be encapsulated, are agitated in a vessel in the presence of spherical contact masses having a mean diameter of less than 3,000 microns, the preferred size range being 50-100 microns in diameter, and resulting in a substantially homogeneous population of vesicles having diameters in the range of about 150 to about 3,000 nanometers. The methods allow for the use of small quantities of marker and lipid, leave no residual solvents, allow for contact only with glass surfaces, and involve no transfer of liposome preparations from lipid film drying vessels to sizing apparatus.

Growing community of inventors

Grayslake, IL, United States of America

Martin Wong