Method for stabilizing hemoglobin and reagents for performing the same
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.
1. A method of stabilizing hemoglobin (Hb) in a stool sample, comprising:
combining the stool sample with a stool resuspension solution comprising a protoporphyrin complexed with Cr 3+ or Co 3+ to produce a suspension,
wherein the protoporphyrin complexed with Cr 3+ or Co 3+ stabilizes Hb in the stool sample.
2. The method of claim 1 , further comprising maintaining the suspension for a period of 3, 4, 5, 6, or 7 days at ambient temperature.
3. The method of claim 1 , further comprising shipping the suspension to a remote location.
4. The method of claim 2 , further comprising shipping the suspension to a remote location.
5. The method of claim 1 , wherein the stool resuspension solution comprises protoporphyrin complexed with Cr 3+ .
6. The method of claim 1 , wherein the stool resuspension solution comprises protoporphyrin complexed with Co 3+ .
7. The method of claim 1 , wherein the protoporphyrin is protoporphyrin IX.
8. The method of claim 5 , wherein the protoporphyrin is protoporphyrin IX.
9. The method of claim 6 , wherein the protoporphyrin is protoporphyrin IX.
10. The method of claim 1 , wherein the stool resuspension solution has a pH in the range of pH 6.5 to pH 7.4.
11. The method of claim 8 , wherein the concentration of protoporphyrin IX complexed with Cr 3+ is 1.25-5 μM.
12. The method of claim 11 , wherein the stool resuspension solution has a pH in the range of pH 6.9 to pH 7.4.
13. The method of claim 8 , wherein the concentration of protoporphyrin IX complexed with Cr 3+ is 1.5-4.5 μM.
14. The method of claim 8 , wherein the concentration of protoporphyrin IX complexed with Cr 3+ is 2.5 μM.
15. The method of claim 14 , wherein the stool resuspension solution has a pH in the range of pH 6.9 to pH 7.4.
16. The method of claim 9 , wherein the concentration of protoporphyrin IX complexed with Co 3+ is 2.5-10 μM.
17. The method of claim 16 , wherein the stool resuspension solution has a pH in the range of pH 6.5 to pH 7.4.
18. The method of claim 9 , wherein the concentration of protoporphyrin IX complexed with Co 3+ is 3-5 μM.
19. The method of claim 1 , wherein the stool resuspension solution comprises a buffer, bovine serum albumin, polysorbate 20, sodium azide, sodium chloride, ethylenediaminetetraacetic acid, and gentamicin.
20. The method of claim 19 , wherein the buffer is Tris buffer.