How long can blood sit before it is centrifuged? When processing blood for serum, manufacturers of evacuated collection tubes often recommend a period of time to allow the blood to clot prior to centrifugation. This may range from 20-30 minutes depending on the manufacturer.
How long can blood go without being spun? Blood collection for serum by venipuncture and handling
If there is no centrifuge, the blood can be kept in a refrigerator (4–8°C) until there is complete retraction of the clot from the serum (no longer than 24 hours).
What happens if you centrifuge blood too long? A prolonged time between blood draw and centrifuging could increase hemolysis , which could impair the stability of 25(OH)D molecules.
Can you spin blood twice? DON’T respin blood in a gel tube after it has been centrifuged to recover additional sample. WHY NOT? Proper gel migration can only occur upon initial spin and subsequent spins will be contaminated with material from cell layer. If a respin is needed, remove an aliquot of serum/plasma and respin that.