Sample depletion and enrichment to improve the quality of diagnostic test results

Abstract

Magnetic and non-magnetic microparticle binding surfaces for the simple, cost-effective and automatable depletion of sample interferences within the assay blocking threshold and enrichment of biomarkers are provided, as are methods and compositions for their preparation and use. The binding surfaces may comprise non-magnetic, magnetic, paramagnetic, and superparamagnetic microparticles, or combinations thereof. The methods include methods for making microparticulate binding surfaces that consist of binders, binding partners, capture moieties, or combinations thereof for multi-functional sample depletion and enrichment. Specific examples employing antibodies or fragments thereof are provided, as well as streptavidin-coated microparticles and microparticles coupled with capture moieties such as immunoglobulins. Other examples couple ligands, enzymes, and proteins, or other biologicals, polymers and chemicals commonly used in the diagnostic test formulation or design. Further provided are binding surfaces consisting of a plurality of microparticles and methods for making them. Use of the methods and compositions in connection with the depletion and enrichment of a wide variety of interferences and biomarkers is provided, particularly for use in primary blood collection tubes, secondary transfer tubes and challenging sample types such as urine, saliva and stool.

What is claimed is: 
     
         1 . A microparticle comprising a microparticulate binding surface, wherein the microparticulate binding surface comprises:
 i) a microparticle support surface;   ii) a binder, binding partner, capture moiety or combinations thereof coupled directly to the support surface; the binder, binding partner, or capture moiety selected from the group consisting of biotin-binding proteins; streptavidin; neutravidin; avidin; biotin-binding fragments of streptavidin; biotin-binding fragments of neutravidin; biotin-binding fragments of avidin; alkaline phosphatase (ALP); horse radish peroxidase (HRP); luminol; isoluminol; ruthenium; acridinium; fluorescein; N-(4-aminobutyl)-N-ethyl-isoluminol (ABEI); biotin; anti-ALP IgG; anti-fluorescein antibody; bovine, goat, mouse, rabbit, sheep, horse, pig, or donkey polyclonal antibodies to target human anti-animal antibodies (HAAA); and mouse IgG, polymerized mouse IgG, Fc fragment of mouse IgG, Fab fragment of mouse IgG, or F(ab′)2 fragment of mouse IgG to target human anti-mouse antibodies (HAMA); and   iii) a binding surface that is blocked with a triblock copolymer selected from the group consisting of Pluronic F108, Pluronic F 127, and Pluronic F68.   
     
     
         2 . A composition comprising the microparticle of  claim 1  and a sample, wherein an interference in the sample is bound to the binder, binding partner, capture moiety or combinations thereof and wherein unbound interference in the sample is below the assay blocking threshold (ABT). 
     
     
         3 . A collection or transfer tube or device comprising the microparticle of  claim 1 . 
     
     
         4 . A collection or transfer tube or device comprising the composition of  claim 2 . 
     
     
         5 . The composition of  claim 2 , wherein the microparticle itself is not an interference. 
     
     
         6 . The microparticle of  claim 1 , wherein the microparticle is magnetic, paramagnetic, or superparamagnetic. 
     
     
         7 . The microparticle of  claim 1 , wherein microparticle support surface comprises a material selected from the group consisting of: ceramic, glass, a polymer, a copolymer, metal, latex, silica, a colloidal metal, gold, silver, alloys, polystyrene, derivatized polystyrene, poly(divinylbenzene), styrene-acylate copolymer, styrene-butadiene copolymer, styrene-divinylbenzene copolymer, poly(styrene-oxyethylene), polymethyl methacrylate, polymethacrylate, polyurethane, polyglutaraldehyde, polyethylene imine, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, N,N′-methylene bis-acrylamide, polyolefins, polyethylene, polypropylene, polyvinylchloride, polyacrylonitrile, polysulfone, poly(ether sulfone), pyrolized materials, block copolymers, and copolymers of the foregoing, silicones, silica, methylol melamine, a biodegradable polymer, dextran, poly(ethylene glycol)-dextran (PEG-DEX), iron oxide, ferromagnetic iron oxide, Fe 2 O 3 , and Fe 3 O 4 , maghemite, and combinations thereof. 
     
     
         8 . The microparticle of  claim 1 , wherein microparticle support surface comprises one or more functional groups for covalent attachment of a binder, binding partner, capture moiety or combinations thereof selected from the group consisting of: carboxyl, tosyl, epoxy, amine, sulfhydryl, hydroxyl, ester, maleimide, azide, alkyne, nitrone, alkene, tetrazine, tetrazole, hydrazone, succinimidyl, succinimidyl-6-hydrazino-nicotinamide, N-succinimidyl-4-formylbenzamide, and photoreactive groups. 
     
     
         9 . The microparticle of  claim 1 , wherein microparticle has a mean diameter of about 0.05 μm to about 3 μm. 
     
     
         10 . The microparticle of  claim 1 , wherein the binder, binding partner, or capture moiety is selected from the group consisting of BSA conjugated to isoluminol, BSA conjugated to ruthenium, BSA conjugated to acridinium, BSA conjugated to fluorescein, and BSA conjugated to N-(4-aminobutyl)-N-ethyl-isoluminol (ABEI). 
     
     
         11 . The microparticle of  claim 1 , wherein the binder, binding partner, or capture moiety comprises biotin-binding proteins; streptavidin; neutravidin; avidin; biotin-binding fragments of streptavidin; biotin-binding fragments of neutravidin; biotin-binding fragments of avidin; alkaline phosphatase (ALP); horse radish peroxidase (HRP); luminol, isoluminol; ruthenium; acridinium; fluorescein; N-(4-aminobutyl)-N-ethyl-isoluminol (ABEI); biotin, anti-ALP IgG, or anti-fluorescein antibody. 
     
     
         12 . The microparticle of  claim 1 , wherein the binder, binding partner, or capture moiety comprises bovine, horse, pig, or donkey polyclonal antibodies to target human anti-animal antibodies (HAAA); or polymerized mouse IgG or Fc fragment of mouse IgG, to target human anti-mouse antibodies (HAMA). 
     
     
         13 . The composition of  claim 2 , wherein the sample is selected from the group consisting of: human serum, animal serum, plasma, blood, whole blood, processed blood, urine, saliva, liquid stool, stool solid, semen, seminal fluid, cells, tissues, biopsy material, DNA, and RNA. 
     
     
         14 . The composition of  claim 2 , wherein the interference is selected from the group consisting of: human anti-mouse antibodies (HAMA), human anti-animal antibodies (HAAA), human anti-goat antibodies, human anti-rabbit antibodies, human anti-sheep antibodies, human anti-bovine antibodies, human anti-mouse antibodies, human anti-horse antibodies, human anti-pig antibodies, human anti-donkey antibodies, biotin, anti-ALP IgG, and anti-fluorescein antibody. 
     
     
         15 . The collection or transfer tube or device of  claim 3 , wherein the tube or device is a primary blood collection tube (PBCT); a secondary transfer tube (SST), a 24-hour urine collection device; a saliva collection tube; a blood spot filter paper; a collection tube or device for stool or seminal fluid; a light green top or green top plasma separator tube (PST) containing sodium heparin, lithium heparin or ammonium heparin; a light blue top tube containing sodium citrate, citrate, theophylline, adenosine, or dipyridamole (CTAD); a red top tube for serology or immunohematology for the collection of serum in a glass (no additives) or plastic tube (contains clot activators); a red top tube for chemistry for the collection of serum in a glass (no additives) or plastic tube (contains clot activators); a purple lavender top tube containing EDTA K2, EDTA K3, liquid EDTA solution, or EDTA K2/gel tubes for testing plasma in molecular diagnostics and viral load detection; a pink top tube for blood bank EDTA; a gray top tube containing potassium oxalate and sodium fluoride, sodium fluoride/EDTA, or sodium fluoride (no anticoagulant); a yellow top tube containing ACD solution A or ACD solution B; a royal blue top (serum, no additive or sodium heparin); or a white top tube. 
     
     
         16 . The collection or transfer tube or device of  claim 4 , wherein the sample is whole blood.