# US 11,994,524 B2 · Method for stabilizing hemoglobin and reagents for performing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,524 B2 - Document ID: US11994524B2 - Status: Granted - Kind: B2 - Application number: 18/101,027 - Filed: 2023-01-24 - Published: 2023-07-13 - Granted: 2024-05-28 - Earliest claimed: 2018-03-27 - Assignees: Exact Sciences Corporation - Applicants: Exact Sciences Corporation - Inventors: Keith D. Fourrier; Jacquelyn T. Hennek; Michael J. Domanico; William G. Weisburg; Graham P. Lidgard; Kathleen S. Harings; Daniel J. Simpson - Web page: https://patentgrep.com/patent/US11994524B2 ## CPC - G01N 33/721: {Haemoglobin} - A61B 10/0038: {Devices for taking faeces samples; Faecal examination devices (anal receptacles A61F5/451)} - G01N 1/02: Devices for withdrawing samples {(sampling of foundation soil E02D1/04; collecting or conveying radioactive samples G01T7/00, e.g. G01T7/02, G01T7/08)} - G01N 1/38: Diluting, dispersing or mixing samples - G01N 33/5094: {for blood cell populations (red blood cells G01N33/80)} - G01N 33/57535: of the large intestine, e.g. colon, rectum or anus - G01N 33/72: involving blood pigments, e.g. haemoglobin, bilirubin {or other porphyrins; involving occult blood} - G01N 33/726: {Devices} - G01N 2333/795: Porphyrin- or corrin-ring-containing peptides - G01N 2333/805: Haemoglobins; Myoglobins - G01N 2800/50: Determining the risk of developing a disease - G01N 2800/52: Predicting or monitoring the response to treatment, e.g. for selection of therapy based on assay results in personalised medicine; Prognosis - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A stool resuspension solution comprising a hemoglobin stabilization reagent is provided. In some embodiments, the hemoglobin stabilization reagent may be an osmolyte, a polyvalent cation, a sugar or polysaccharide and, optionally, a polyvalent cation, a protoporphyrin, or an HRP stabilization component and, optionally, a polyvalent cation. A method of stabilizing hemoglobin in a stool sample in the solution is also provided, as well as a sample collection device containing the solution. ## Claims ### Claim 1 A stool resuspension solution effective to stabilize hemoglobin, the solution comprising: protoporphyrin complexed with Cr3+, or protoporphyrin complexed with Co3+, wherein the protoporphyrin complexed with Cr3+ or Co3+ is effective to stabilize hemoglobin. ### Claim 2 (depends on 1) The stool resuspension solution of claim 1, wherein the concentration of the protoporphyrin complexed with Cr3+ is 1.25-5 μM. ### Claim 3 (depends on 1) The stool resuspension solution of claim 1, wherein the concentration of the protoporphyrin complexed with Co3+ is 2.5-10 μM. ### Claim 4 (depends on 1) The stool resuspension solution of claim 1, wherein the concentration of the protoporphyrin complexed with Cr3+ is 1.5-4.5 μM. ### Claim 5 (depends on 1) The stool resuspension solution of claim 1, wherein the concentration of the protoporphyrin complexed with Co3+ is 3-5 μM. ### Claim 6 (depends on 1) The stool resuspension solution of claim 1, wherein the protoporphyrin is protoporphyrin IX. ### Claim 7 (depends on 1) The stool resuspension solution of claim 1, wherein the solution has a pH in the range of pH 6.5 to pH 7.4. ### Claim 8 (depends on 2) The stool resuspension solution of claim 2, wherein the pH of the solution is in the range of pH 6.9 to pH 7.4. ### Claim 9 (depends on 3) The stool resuspension solution of claim 3, wherein the pH of the solution is in the range of pH 6.5 to pH 7.4. ### Claim 10 (depends on 1) The stool resuspension solution of claim 1, wherein a stool sample is suspended in the solution. ### Claim 11 (depends on 1) The stool resuspension solution of claim 1, further comprising a buffer, bovine serum albumin, polysorbate 20, sodium azide, sodium chloride, ethylenediaminetetraacetic acid, and gentamicin. ### Claim 12 A stool sample collection device comprising: a stool sample collection container having an open end; and a stool resuspension solution comprising protoporphyrin complexed with Cr3+ or Co3+, wherein the protoporphyrin complexed with Cr3+ or Co3+ is effective to stabilize hemoglobin. ### Claim 13 (depends on 12) The stool sample collection device of claim 12, further comprising a stool sampling rod comprising a distal beveled tip for scooping and/or scraping a sample of stool, wherein the distal end of the sampling rod is dimensioned to be inserted into the sample collection container and the proximal end of the sampling rod is adapted to connect with the open end of the sample collection container, thereby sealing the distal end of the sampling rod within the device. ### Claim 14 (depends on 13) The stool sample collection device of claim 13, wherein the sample collection container and sampling rod connect via a screw fit. ### Claim 15 (depends on 12) The stool sample collection device of claim 12, wherein the concentration of the protoporphyrin complexed with Cr3+ is 1.25-5 μM. ### Claim 16 (depends on 12) The stool sample collection device of claim 12, wherein the concentration of the protoporphyrin complexed with Co3+ is 2.5-10 μM. ### Claim 17 (depends on 12) The stool sample collection device of claim 12, wherein the concentration of the protoporphyrin complexed with Cr3+ is 1.5-4.5 μM and wherein the concentration of the protoporphyrin complexed with Co3+ is 3-5 μM. ### Claim 18 (depends on 12) The stool sample collection device of claim 12, wherein the protoporphyrin is protoporphyrin IX. ### Claim 19 (depends on 15) The stool sample collection device of claim 15, wherein the solution has a pH in the range of pH 6.5 to pH 7.4. ### Claim 20 (depends on 16) The stool sample collection device of claim 16, wherein the pH of the solution is in the range of pH 6.9 to pH 7.4.