Solid-phase immunoassays using magnetic glass

• US 4,297,337 A
• Filed: 04/13/1979
• Issued: 10/27/1981
• Est. Priority Date: 04/13/1979
• Status: Expired due to Term

• Current Assignee: CIBA Vision Corporation (Bayer AG)
• Original Assignee: Corning Glass Works Inc. (Corning Incorporated)
• Inventors: Vann, William P., Travis, Karen L., Mansfield, Gerald R.
• Primary Examiner(s): Padgett, Benjamin R.
• Assistant Examiner(s): Nucker, Christine M.
• Application Number:
  US06/029,576
• Time in Patent Office: 928 Days
• Field of Search: 23/230 B, 424/1, 424/1.5, 424/12
• US Class Current: 436/527
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G11B 5/70626 containing non-metallic substances
• CPC Class Codes: Y10S 436/804 Radioisotope, e.g. radioimmunoassay
• CPC Class Codes: Y10S 436/808 Automated or kit
• CPC Class Codes: Y10S 436/817 Steroids or hormones

Abstract

Solid-phase immunoassay procedures employing magnetic glass or crystal-containing material, or a superparamagnetic material formed of magnetic particles dispersed in a non-magnetic matrix, as particulate carrier.

Claims

1. In a process for carrying out a solid-phase immunoassay wherein a biological material is complexed with a water-insoluble, inert particulate carrier and, during the assay, the particulate carrier is separated from a fluid, the improvement which comprises utilizing, as said particulate carrier, water-insoluble, inert, magnetically-dilute particles of a glass and/or crystal-containing material having iron-containing, magnetic crystals incorporated therein with dimensions of less than about 1000 A which are essentially enveloped within the glass and/or crystal structure, and magnetically separating said particulate carrier from said fluid.

2. A process according to claim 1 wherein said biological material is an antigen, a hapten, an enzyme, or an antibody.

3. A process according to claim 1 wherein said glass and/or crystal-containing material consists of a crystalline ceramic.

4. A process according to claim 1 wherein said glass and/or crystal-containing material consists of a glass.

5. A process according to claim 4 wherein said glass has a composition in the alkali metal-iron-borosilicate system.

6. A process according to claim 1 wherein said glass and/or crystal-containing material consists of a crystal-containing material.

7. A process according to claim 1 wherein said magnetic crystals are selected from the group of gamma iron oxide, magnetite, a ferrite, and mixtures thereof.

8. A process according to claim 1 wherein said magnetic crystals constitute less than 20% by volume of said particulate carrier.

9. A process according to claim 1 wherein said water-insoluble, inert, magnetically-dilute particles are porous.

10. A process according to claim 1 wherein said particles consist of a crystalline ceramic.

11. A process according to claim 9 wherein said particles consist of glass.

12. A process according to claim 11 wherein said particles are composed of a porous skeleton consisting essentially of vitreous silica with said magnetic crystals dispersed therewithin.

13. A process according to claim 12 wherein said magnetic crystals constitute less than 20% by volume of said particles.

14. A process according to claim 9 wherein said particles consist of a crystal-containing material.

15. A process according to claim 14 wherein said particles are composed of a glassy crystalline skeleton with said magnetic crystals enveloped therewithin, said glass consisting essentially of vitreous silica and said crystal phase consisting essentially of a silica-containing species.

16. A process according to claim 15 wherein said magnetic crystals constitute less than 20% by volume of said particles.

17. A process according to claim 1 wherein a surfactant is incorporated into said fluid during the separation operation.

18. A solid-phase immunoassay reagent consisting essentially of water-soluble, inert, magnetically-dilute carrier particles having biological material carried on the surface thereof, which particles consist essentially of a glass and/or crystal-containing material having iron-containing, magnetic crystals incorporated therein with dimensions of less than about 1000 A which are essentially enveloped within the glass and/or crystal structure.

19. A reagent according to claim 18 wherein said biological material is an antigen, a hapten, an enzyme, or an antibody.

20. A reagent according to claim 18 wherein said glass and/or crystal-containing material consists of a crystalline ceramic.

21. A reagent according to claim 18 wherein said glass and/or crystal-containing material consists of a glass.

22. A reagent according to claim 21 wherein said glass has a composition in the alkali metal-iron-borosilicate system.

23. A reagent according to claim 18 wherein said glass and/or crystal-containing material consists of a crystal-containing material.

24. A reagent according to claim 18 wherein said magnetic crystals are selected from the group of gamma iron oxide, magnetite, a ferrite, and mixtures thereof.

25. A reagent according to claim 18 wherein said magnetic crystals constitute less than 20% by volume of said carrier particles.

26. A reagent according to claim 18 wherein said particles are porous.

27. A reagent according to claim 26 wherein said particles consist of a crystalline ceramic.

28. A reagent according to claim 26 wherein said particles consist of glass.

29. A reagent according to claim 28 wherein said particles are composed of a porous skeleton consisting essentially of vitreous silica with said magnetic crystals dispersed therewithin.

30. A reagent according to claim 29 wherein said magnetic crystals constitute less than 20% by volume of said particles.

31. A reagent according to claim 26 wherein said particles consist of a crystal-containing material.

32. A reagent according to claim 31 wherein said particles are composed of a glassy-crystalline skeleton with said magnetic crystals enveloped therewithin, said glass consisting essentially of vitreous silica and said crystal phase consisting essentially of a silica-containing phase.

33. A reagent according to claim 32 wherein said magnetic crystals constitute less than 20% by volume of said particles.

34. A radioimmunoassay kit containing the reagent of claim 18.