STABILIZATION OF SIGNAL GENERATION IN PARTICLES USED IN ASSAYS

• US 20110091978A1
• Filed: 10/21/2009
• Published: 04/21/2011
• Est. Priority Date: 10/21/2009
• Status: Active Grant

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Inventors: Teng, Zhu, Moran, Christine, Snyder, Jason, Schelp, Carsten, Craig, Alan R.
• Granted Patent: US 8,153,442 B2
• Time in Patent Office: Days
• US Class Current: 436/8
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/76 Chemiluminescence; Bioluminescence
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: Y10S 435/968 High energy substrates, e.g. fluorescent, chemiluminescent, radioactive
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/2525 Stabilizing or preserving

Abstract

Methods and reagents are disclosed for conducting assays. Embodiments of the present methods and reagents are concerned with a solid support such as, for example, a particle. The support comprises a chemiluminescent composition that comprises a metal chelate. The present inventors observed that, when such support such as, e.g., particles, were employed in assays for the determination of an analyte, stability of signal output by the chemiluminescent composition associated with the particle was unacceptably reduced as compared to particles comprising other chemiluminescent compositions. In accordance with embodiments of the present invention, the stability of signal output from such particles is enhanced by including in a medium comprising the particles a sufficient amount of one or more stabilizing agents, which may be a chelating agent and/or a metal chelate such as, for example, the metal chelate that is associated with the particle.

Claims

1. A method of enhancing the stability of a chemiluminescent reagent comprising a solid support having associated therewith a chemiluminescent composition comprising a complex of a metal and one or more chelating agents, the method comprising incorporating into a medium comprising the chemiluminescent reagent one or more stabilizing agents selected from the group consisting of metal chelating agents and metal chelates in an amount sufficient to enhance the stability of the chemiluminescent reagent.

2. The method according to claim 1 wherein the stabilizing agent is a metal chelating agent of the complex.

3. The method according to claim 1 wherein the metal is a rare earth metal or a metal of Group VIII.

4. The method according to claim 1 wherein the metal is selected from the group consisting of europium, terbium, dysprosium, samarium osmium and ruthenium.

5. The method according to claim 1 wherein the metal is europium, the chelating agent is NHA and DPP and the stabilizing agent comprises NBA or NHA and DPP.

6. The method according to claim 1 wherein the solid support is a particle.

7. The method according to claim 1 wherein the solid support is a latex particle.

8. The method according to claim 1 wherein the complex is incorporated in the solid support.

9. The method according to claim 1 wherein a member of a specific binding pair is associated with the solid support.

10. A chemiluminescent reagent for determining the presence and/or amount of an analyte in a sample suspected of containing the analyte, the reagent comprising in a medium a solid support having associated therewith a member of a specific binding pair and having incorporated therein a complex of a metal and one or more chelating agents, wherein the medium further comprises one or more stabilizing agents selected from the group consisting of chelating agents and metal chelates, the amount of the one or more stabilizing agents being sufficient to enhance the stability of the chemiluminescent reagent.

11. The reagent according to claim 10 wherein the stabilizing agent is a chelating agent of the complex.

12. The reagent according to claim 10 wherein the metal is a rare earth metal or a metal of Group VIII.

13. The reagent according to claim 10 wherein the metal is selected from the group consisting of europium, terbium, dysprosium, samarium osmium and ruthenium.

14. The reagent according to claim 10 wherein the solid support is a particle.

15. The reagent according to claim 10 wherein the solid support is a latex particle.

16. The reagent according to claim 10 wherein the complex is incorporated in the solid support.

17. The reagent according to claim 10 wherein the solid support further comprises a photosensitizer associated therewith.

18. The reagent according to claim 10 wherein the metal is europium, the chelating agent is NHA and DPP and the stabilizing agent comprises NHA or NHA and DPP.

19. A method for determining the presence and/or amount of an analyte in a sample suspected of containing the analyte, the method comprising:

(a) providing in combination in a medium;

(i) the sample,

(ii) the chemiluminescent reagent of claim 10, and

(iii) a photosensitizer associated with a particle and being capable of generating singlet oxygen, wherein a specific binding pair member for the analyte is associated with at least one of the solid support or the particle,

(b) subjecting the combination to conditions for binding of the analyte to the specific binding pair member for the analyte, and

(c) irradiating the photosensitizer with light and detecting the amount of luminescence generated by the chemiluminescent composition, the amount of luminescence being related to the amount of the analyte in the sample.

20. The method according to claim 19 wherein the particle with which the photosensitizer is associated is the solid support of the chemiluminescent reagent.

21. The method according to claim 19 wherein the metal is europium, the chelating agent is NHA and DPP and the stabilizing agent comprises NHA or NHA and DPP.