Stabilization of whole blood samples

1. A method of stabilizing a sample of whole blood, the method comprising

obtaining a sample of whole blood comprising viable, unfixed cells from a subject, and introducing the sample into a container containing an anticoagulant;

introducing to the sample a preservative formulation that comprises 24-48 mM HEPES, 0.11-0.44 mM adenine, 2.25-6.75 mM mannitol, 0.39-1.54 mM N-acetyl-L-cysteine, 0-13.5 mM dextrose, and 0-17 mM NaCl;

introducing to the sample a caspase inhibitor, a platelet inhibitor, or both a caspase inhibitor and a platelet inhibitor; and

maintaining the sample of whole blood at 2-25° C. for at least 24 hours, thereby stabilizing the viable, unfixed cells in the sample of whole blood.

2. The method of claim 1 , further comprising adding a Ficoll® polymer to the sample of whole blood.

3. The method of claim 2 , wherein the Ficoll® polymer comprises is Ficoll® 70 and is added to produce a concentration of at least 10% Ficoll® 70 in the sample of whole blood.

4. The method of claim 1 , wherein a caspase inhibitor is added to the sample of whole blood, and wherein the caspase inhibitor is selected from the group consisting of Q-VD-OPh ((3 S)-5-(2,6-difluorophenoxy)-3-[[(2 S)-3-methyl-2-(quinoline carbonylamino)butanoyl]amino]-4-oxopentanoic acid), Z-VAD-FMK (methyl (3S)-5-fluoro [[(2S)-2-[[(2S)-3-methyl-2-(phenylmethoxycarbonylamino)butanoyl]amino]propanoyl]amino]-4-oxopentanoate), Q-VD(OMe)-OPh ((S)-methyl 5-(2,6-difluorophenoxy)-3-((S)-3-methyl (quinoline-2-carboxamido)butanamido)-4-oxopentanoate), or Boc-D-fmk (methyl 5-fluoro-3-[(2-methylpropan-2-yl)oxycarbonylamino]-4-oxopentanoate).

5. The method of claim 1 , wherein sufficient caspase inhibitor is added to the sample of whole blood to achieve a final concentration of 2-10 μM.

6. The method of claim 1 , wherein the preservative formulation comprises 48 mM HEPES, 0.44 mM adenine, 6.75 mM mannitol, 0.77 mM N-acetyl-L-cysteine, and 8.5 mM NaCl.

7. The method of claim 1 , wherein a platelet inhibitor is introduced to the sample of whole blood.

8. The method of claim 7 , wherein the platelet inhibitor is selected from the group consisting of ticagrelor, cilostazol, prasugrel, dipyridamole, prasugrel, Tirofiban, eptifibatide, clopidogrel, or KF38789.

9. The method of claim 1 , wherein a platelet inhibitor is added to the sample of whole blood to achieve a final concentration of from 0.01-100 μg/mL.

10. The method of claim 1 , wherein the sample of whole blood is stored at 4° C.

11. The method of claim 9 , wherein the platelet inhibitor is added to the sample of whole blood to achieve a final concentration of from 0.01-0.5 μg/mL.

12. The method of claim 1 , further comprising incubating the sample of whole blood with adenosine.