Blood Drug Testing

Only 1 drp of blood is requird for blood-tests, then why do they take so much of blood at labs for the purpos?

Every time you go to a lab for any blood test, they take too much of blood out of your body, but only one or a few drops are required for testing purposes! Then why do they take that much of blood? Where does it go?

Public Comments

1. To feed the vampires they keep hidden at the laboratories.
2. Most doctors actually belong to secret cults of Vampirism. They must have that extra blood in order to not vanish in a puff of smoke in open daylight. Go to Yahoo! Shrinks & Ghouls for more information. If you dare.
3. That's not necessarily true. Some tests take quite a lot of blood. It depends on which test(s) you're having. For the ones that do take only a drop often it takes a drop of serum which makes up about half of blood and that has to be separated from the cells in a centrifuge so we need a minimum amount for that. Also, it's very common for a doctor to add several tests on to a patient's orders after they've had their blood drawn so it's a common practice to draw extra blood in case they order tests that require more blood. Also, some tests require that the blood be in a very specific ratio to the amount of anticoagulant in the tube for the analyzer to be able to give good results. In the end, the unused blood is discarded. Don't worry though...it's not as much as it seems. I don't know if you've ever given a unit of blood, but there are about 60 of the largest tubes we would use in that amount.
4. they might drop a vial..also,they preserve 1 vial for later dna work and classification once it become legal...all labs have been doing that since 2002
5. as punishment for not eating you veggies
6. So they can take multiple tests. The rest of the blood may be just disposed of in medical waste, or , with your permission, they may send it to a blood bank.
7. usually, medical technologists, and nurses get 3 ml of blood.. you cant do anything with just one drop of blood..
8. It depends on what test is being performed. Some tests require serum which is blood minus all the cells in the blood. A drop of blood is not enough for seperating the serum from blood. Nowadays most labs perform the tests on auto analyzers. Suppose the test value is abnormal they have to repeat the test and if they get the same result, sometimes they would also do a manual test for confirming the result. If multiple tests are involved, then they would draw lot of blood. And the lot of blood that appears to you that is 5-6 mL of blood is actually not a lot.
9. I work in a lab and can tell you that they take more blood then needed because some of the machines they run the tests on require more. Also, most lab tests call for serum only, which is what is left when you seperate the red blood cells which takes more specimen to get more serum to perform the test, and alot of doctors are known to call a couple days later and add more tests onto the original order. So we take more blood to accomodate the doctors requests. in the lab I work in, the extra blood is saved in a refridgerator for five days just in case the doc wants to add more tests. After the five days, the specimens are simply discarded.