Claims for Patent: 4,298,685

Summary for Patent: 4,298,685

Title:	Diagnostic reagent
Abstract:	A sample, e.g. serum, containing an antigen, hapten or other biological substance is mixed with antibodies raised against that substance which have been tagged with biotin, and with a known amount of that substance labelled with an enzyme. After the competitive complexation of the antibody with the labelled substance and the substance to be detected, avidin, immobilised on an inert support is added. The avidin binds to the biotin and causes the complex to be precipitated. The solid and liquid phases are separated by centrifugation and the amount of biological substance in the original sample is determined by measuring the activity of the enzyme in either phase.
Inventor(s):	Parikh; Indu (Chapel Hill, NC), Cuatrecasas; Pedro (Chapel Hill, NC)
Assignee:	Burroughs Wellcome Co. (Research Triangle Park, NC)
Application Number:	06/035,619
Patent Claims:	1. A process for the quantitative determination of a biological substance in a test sample comprising, (a) mixing said test sample, a soluble enzyme-labelled form of said biological substance, and a soluble biotin-tagged antibody raised against said biological substance, (b) incubating the mixture under conditions suitable for forming an antibody-biological substance complex, (c) then adding isolubilized avidin, separating the resulting solid phase from the liquid phase, and (d) determining the enzyme activity of either of said phases. 2. A process as claimed in claim 1 wherein said enzyme of said substance is selected from the group consisting of malate dehydrogenase, staphylococcal nuclease, delta-5-ketosteroid isomerase, yeast alcohol dehydrogenase, yeast glucose-6-phosphate dehydrogenase, alpha glycerophosphate dehydrogenase, triose phosphate, isomerase, horse radish peroxidase, alkaline phosphatase, asparaginase, glucose oxidase, beta-galactosidase and ribonuclease. 3. A process as claimed in claim 1 or 2 wherein the avidin is insolubilised by covalent binding to a macromolecular insoluble carrier. 4. A process as claimed in claim 3 wherein said macromolecular insoluble carrier is selected from the group consisting of agarose, polystyrene, polyacrylamide, nylon, cross-linked dextran and filter paper. 5. A process as claimed in claim 4 wherein said macromolecular insoluble carrier is agarose. 6. A process as claimed in claim 1 wherein the avidin is insolubilised by physical coupling to an insoluble carrier. 7. A process as claimed in claim 6 wherein said insoluble carrier is selected from the group consisting of glass beads, plastic objects, the inside of plastic test tubes, the inside of glass test tubes and microtitre plates. 8. A process as claimed in claim 1; wherein said biological substance is an antigen. 9. A process as claimed in claim 1 wherein said biological substance is a hapten. 10. A process as claimed in claim 1 wherein said biological substance is digoxin or codeine. 11. A kit for use in enzyme immunoassay comprising, (a) a quantity of enzyme-labelled biological substance, (b) a quantity of biotin-tagged antibody raised against said biological substance, (c) a quantity of insolubilized avidin, and (d) a quantity of substrate for said enzyme, wherein said quantity of biotin tagged antibody is sufficient to bind a substantial quantity of the enzyme-labelled substance, said quantity of insolubilized avidin is present in excess of the amount required to precipitate the biotin tagged antibody, and said quantity of said substrate is sufficient to react with said enzyme label to produce a detectable signal. 12. A kit as claimed in claim 11 wherein the enzyme is selected from the group consisting of malate dehydrogenase, staphylococcal nuclease, delta-5-ketosteroid isomerase, yeast alcohol dehydrogenase, yeast glucose-6-phosphate dehydrogenase, alpha glycerophosphate dehydrogenase, triose phosphate isomerase, horse radish peroxidase, alkaline phosphatase, asparaginase, glucose oxidase, beta-galactosidase and ribonuclease. 13. A kit as claimed in claim 11 wherein the avidin is insolubilised by covalent binding to a macromolecular insoluble carrier. 14. A kit as claimed in claim 13 wherein said macromolecular insoluble carrier is selected from the group consisting of agarose, polystyrene, polyacrylamide, nylon cross-linked dextran and filter-paper. 15. A kit as claimed in claim 14 characterised in that said macromolecular insoluble carrier is agarose. 16. A kit as claimed in claim 11 wherein the avidin is insolubilised by physical coupling to an insoluble carrier. 17. A kit as claimed in claim 16 wherein said insoluble carrier is selected from the group consisting of glass beads, plastic objects, the inside of a test tube made from plastic and the inside of a test tube made from glass. 18. A kit as claimed in any one of claims 11 to 17 wherein said biological substance is digoxin or codeine.

Details for Patent 4,298,685

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Recordati Rare Diseases, Inc.	ELSPAR	asparaginase	For Injection	101063	01/10/1978		1998-11-03