Question about blood...

It really depends what the blood is going to be used for. Blood samples taken by doctors are put in vials with a substance to preserve the sample. Blood samples taken by a layman and put in plain vials would clot, and not be suitable for testing. As for how long either would last unrefrigerated, I'm not sure. I doubt it's very long. A baggy of ice might work short-term but again, I'm not sure. Maybe someone else here has more medical knowledge than I do.

According to the abstract of one paper I found, blood remains viable unrefrigerated up to 8 hrs if treated with the anticoagulant CPDA-2 and up to about 49 days if refrigerated and treated.

An hour or two on ice in a baggie is fine. I've left blood samples on ice in a cooler for hours myself, but it is best to get them to the freezer/fridge asap. That was for later use in chemical analysis and the results came back fine - so no big deal.

If the tube does not have EDTA or another preservative it will coagulate very quickly.

I'm pretty sure there are tubes with no EDTA in them, but they probably are specific for protocols in which the EDTA would intract with another chemical during analysis. SO long story short, most tubes already have that preservative in them so that can be an assumption. Anyone who is that interested in the allotted time for blood to coagulate has probably drawn blood themselves and understands this point.



The Ice thing was actually a big beef with me in "I am Legend" (Movie). He didn't give her ice to put the blood sample in...would have been worthless.

My kids appreciated me ruining the end like that...

Blood from a wound will clot fairly quickly. Unless the person has a clotting disorder, takes a clotting inhibitor or is in a tub of warm water.

Blood exposed to air will also clot quickly. I had a patient who pulled her IV line apart and was on a Heparin drip (blood thinner). Her IV backed up and she bled profusely in a very short time (change of shift--I was oncoming and when I went on first rounds, found her). The clot on the bed looked and felt like a human liver.

Still, she lived. Not sure how. Her circulating volume had to be low.

You may want to introduce yourself in the newbee side of the AW. I see this is your first post.

This is an aside, but once after my husband bagged a deer, I saw that some of the blood had congealed in the bed of his pickup truck. (This was about twelve hours after the animal was shot.) Amazingly, it really did look like raspberry jam. I had always figured that for a myth.

Sorry...I know that wasn't really the point of the post, but that incident has always stuck in my head.