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

Inventors

Soldo, Joshua Caine

Assignees

Veravas Inc

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 strepavidin-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.

Core Innovation

The disclosed invention provides a method of depleting heterophilic sample interferences from a sample prior to a diagnostic test by preanalytical processing. The method uses a microparticle comprising a microparticulate binding surface that is combined with a sample, mixed, and incubated so that heterophilic interferences and interference mechanisms bind and are captured by the microparticulate binding surface.

After incubation, the microparticulate binding surface is separated, removed, or eliminated to prepare an essentially microparticulate binding surface-free sample supernatant prior to the diagnostic test. The microparticulate binding surface comprises a microparticle support surface and a binder, binding partner, or capture moiety coupled to the support surface, and the binding surface is blocked with a triblock copolymer.

The triblock copolymer is Pluronic F108, Pluronic F127, or Pluronic F68. The disclosure includes biotin-binding proteins, alkaline phosphatase, horse radish peroxidase, luminol, isoluminol, ruthenium, acridinium, fluorescein, N-(4-aminobutyl)-N-ethyl-isoluminol, polyclonal antibodies to target HAAA, and IgG-related fragments including Fc, Fab, and F(ab’)2 fragments to target HAMA.

The disclosure further addresses assay design parameters through an Assay Blocking Threshold and includes diagnostic contexts for sample types such as blood, urine, saliva, and stool. Example workflows and embodiments support depletion and optional enrichment prior to diagnostic testing, including biomarker enrichment using biomarker-targeting microparticles.

Claims Coverage

The provided material includes one independent claim. Across the claim set, inventive features focus on a microparticle-based preanalytical depletion workflow, a specifically blocked microparticulate binding surface with defined binder/capture moieties targeting heterophilic interference, separation/removal to obtain an essentially microparticulate binding surface-free sample supernatant, and depletion to within an Assay Blocking Threshold.

The inventive approach is to deplete heterophilic sample interferences prior to a diagnostic test using microparticles with a triblock-copolymer blocked microparticulate binding surface, defined binder/capture moieties for capturing heterophilic interference mechanisms, and separation/removal to provide an essentially microparticulate binding surface-free sample supernatant within an Assay Blocking Threshold.

Stated Advantages

Documented Applications