and collect the blood sample by just letting it drip into the vial rather than having it collected through the tube...would test results be inaccurate since it was exposed to more oxygen? (Granted, of course,......
When you cut yourself, you may be drawing blood from either a capillary vein or artery, but there is no way to tell precisely which.
"Does exposure to oxygen effect it in any other way besides color? For example, if I were to prick myself, and collect the blood sample by just letting it drip into the vial rather than having it collected through the tube...would test results be inaccurate since it was exposed to more oxygen?" (Granted, of course, that it hasn't been contaminated by something else during the trip from my arm to the lab) -- Exposure of blood to oxygen does not alter the results of a regular test. However, the fact that you let the blood drip into the vial can affect some other parameters:
- the mixing with the anticoagulant
- the contamination with anything that may be on your skin
- the fact that the moment you begin to bleed your platelets begin to heal the wound, causing the inaccuracy of other parameters.
"Inside our bodies, blood is more of a dark purple-ish color; It's the exposure to oxygen that makes it look red when we get cut, right?"
Nope. Completely untrue. It's a common myth caused by the fact that deoxygenated blood looks sort of bluish in our veins. This is due to an optical illusion. Wanna know how we know that?
"But I've noticed that when I give a blood test, the blood looks rather dark as it's being collected into the clear vials. It still has a hint of red, but it's much much darker than it is when I've cut myself and collected it on a towel."
This. You have yourself made an observation that disproves the myth.
"Does it just appear darker because there's so much in the vial, or has it actually been unexposed to oxygen and still the same color as it was inside me?"
It's the same color as it is inside you.
"For example, if I were to prick myself, and collect the blood sample by just letting it drip into the vial rather than having it collected through the tube...would test results be inaccurate since it was exposed to more oxygen?"
Depends on the test. I'm not aware of any lab tests that require unoxygenated blood, but I don't do hospital lab tests.
