Method for reduction of interferences in immunoassays

1. An immunoassay method for detecting an analyte in an isolated sample suspected to contain said analyte comprising:

incubating said sample with a plurality of binding partners, wherein one binding partner carries a detectable label and is capable of binding to the analyte and another binding partner is a label-specific binding partner that does not carry a label but binds to said detectable label, wherein the label-specific binding partner is a biological molecule based on a polypeptide composed of amino acids, wherein the incubating is maintained for a time period sufficient for allowing said analyte, if present in the sample, to bind with said binding partner carrying the detectable label thus forming an immunoreaction product; and

detecting the presence of said immunoreaction product directly or indirectly via the detectable label.

2. An immunoassay method according to claim 1 , comprising:

a. incubating said sample with

i. a first binding partner that binds to the analyte and that carries a detectable label;

ii. a second binding partner that is capable of being bound to a solid phase and that binds to the analyte; and

iii. a third binding partner that binds to said detectable label of said first binding partner, wherein said third binding partner does not carry a label, wherein said third binding partner is a biological molecule based on a polypeptide composed of amino acids;

b. forming an immunoreaction admixture by admixing said sample with said first, second and third binding partners;

c. maintaining said immunoreaction admixture for a time period sufficient for allowing said analyte if present in the body fluid sample to immunoreact with said first and second binding partners to form an immunoreaction product; and allowing said third binding partner to immunoreact with said detectable label of said first binding partner; and

d. detecting at least one of the presence and the concentration of any of said immunoreaction product.

3. An immunoassay method according to claim 1 , comprising:

a. incubating said sample with

i. a first binding partner that binds to the analyte and that does not carry a detectable label;

ii. a specifier which binds to the first binding partner and which competes with the analyte for binding to the first binding partner wherein said specifier carries a detectable label;

iii. a second binding partner that is capable of being bound to a solid phase and that binds to said first binding partner and which competes with said analyte and said specifier for binding to said first binding partner; and

iv. a third binding partner that binds to said detectable label of said specifier, wherein said third binding partner does not carry a label, wherein said third binding partner is a biological molecule based on a polypeptide composed of amino acids;

b. forming an immunoreaction admixture by admixing said sample with said first, second and third binding partners and said specifier;

c. maintaining said immunoreaction admixture for a time period sufficient for allowing said analyte if present in said body fluid sample to compete with said specifier and second binding partner for binding to said first binding partner, and allowing said third binding partner to immunoreact with said detectable label of said specifier, thereby forming an immunoreaction product; and

d. detecting at least one of the presence and the concentration of any of said immunoreaction product.

4. An immunoassay method according to claim 1 wherein said analyte is selected from the group consisting of a biological and a chemical molecule associated with at least one of an infection, an inflammatory, septic, metabolic, cardiac, and an oncologic event or disease.

5. An immunoassay method according to claim 4 wherein said analyte is selected from the group consisting of a hormone, an antigen and an antibody.

6. An immunoassay method according to claim 5 wherein said analyte is an antibody against a pathogen selected from the group consisting of

a. a Toxoplasma organism;

b. a hepatitis virus; and

c. a herpes virus;

d. rubella virus;

e. a retrovirus;

f. paramyxoviruses; and

g. a Borrelia organism.

7. An immunoassay method according to claim 6 wherein said analyte is an antibody of the IgM class.

8. An immunoassay method according to claim 7 wherein said analyte is an antibody of the IgM class present as a reaction to an infection with a pathogen selected from the group consisting of Toxoplasma gondii, cytomegalovirus (CMV), Rubella, hepatitis A and hepatitis B.

9. An immunoassay method according to claim 1 wherein said detectable label is selected from the group consisting of an enzymatic, radioactive, luminescent, chemiluminescent and electrochemiluminescent label.

10. A reagent kit for detecting an analyte by an immunoassay comprising a plurality of binding partners wherein at least one of the binding partners binds to the analyte, and one of the binding partners carries a detectable label and one of the binding partners is label-specific and binds to said detectable label but does not carry a detectable label, wherein the label-specific binding partner is a biological molecule based on a polypeptide composed of amino acids.

11. An immunoassay method according to claim 6 wherein said a pathogen is Toxoplasma gondii.

12. An immunoassay method according to claim 6 wherein said a pathogen is a hepatitis virus selected from the group consisting of hepatitis A virus (HAV), hepatitis B virus (HBV) and hepatitis C virus (HCV).

13. An immunoassay method according to claim 6 wherein said pathogen is a herpes virus selected from the group consisting of human herpes simplex virus 1 and 2 (HHV1 and HHV2), varicella zoster virus (HHV3), Epstein-Barr virus (HHV4/EBV) or human cytomegalovirus (HHV5) and human herpes viruses 6, 7, and 8.

14. An immunoassay method according to claim 6 wherein said pathogen is a retrovirus selected from the group consisting of human immunodeficiency virus (HIV) 1 and 2 and human T-lymphotropic virus (HTLV) 1 and 2.

15. An immunoassay method according to claim 6 wherein said pathogen is a paramyxoviruses selected from the group consisting of measles virus and mumps virus.