Talk:Phlebotomist

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If a hematocrit is done on-site and quickly in time to determine if the person can donate blood. I don't know much about the process, but the article on hematocrit seems to imply it takes some time to do. Can anyone provide a source that says what sort of iron test is actually done? Also see discussion at Talk:Blood donation. --zandperl 03:13, 12 Apr 2004 (UTC)

• A hematocrit is designed for speed: a few minutes to spin the blood down is all it takes. Almost certainly no "iron test" is done: the website is amateurishly equating hemoglobin/hematocrit levels with iron levels. Equally certainly, different tests are done in different nations: a generic description might be that "a test is done to ensure the donor is not anemic". - Nunh-huh 03:18, 12 Apr 2004 (UTC)

• • A hematocrit would be too difficult (and take too long) in many blood donation places. Plus it's more likely you'll get samples mixed up.
  • They wouldn't do an iron test, as this is done on serum and doesn't give much info as to the iron status of the patient.
  • I gave blood about five/six years ago (i should again), they fingerpricked me, put the blood in a small machine, and told me i had borderline haemoglobin (was 135 g/L or something, don't worry, 160 g/L now).
  • People often call Hb and iron test T 03:32, 12 Apr 2004 (UTC)

Blood donation is different in different places. Not everyone has a colorimetric test available; not everyone has a centrifuge. Different places uses different ways of assessing the donor for anemia (anemia, not "iron levels"). Not everyone follows the practice followed in the last place any particular editor has donated blood. And people who call a hemoglobin level an iron test are... wrong. Just as the people who apparently (at Blood donation) call a blood density test an "iron test" are wrong. It's worth being particular on this point: we don't need to encourage the erroneous idea that all anemia is iron deficiency anemia. -- Nunh-huh 03:42, 12 Apr 2004 (UTC)

I realise that people who call Hb an iron test are wrong. But if you ask what the fingerprick is for you'll no doubt hear "it's to test your iron". My point, (which may be wrong!), was that haemoglobin is more likely to be called iron in the reference than hematocrit.

But yeah, you're right about the hematocrit being used by some places. [1] T 23:20, 12 Apr 2004 (UTC)

The same people who tell you "it's to test your iron" will also tell you "this won't hurt a bit"<g>. My point was that it's not to test your iron. You may be right that they are more likely to say it's for iron if they're using a colorimeter, because that's much more of a paint-by-numbers test: you don't need to know anything about the way it works to do it, which is probably not true of hematocrit. - Nunh-huh 23:30, 12 Apr 2004 (UTC)

So between this talk page and Talk:Blood donation I have heard of the following tests:

• generic "iron test"
• hematocrit
• hemoglobin quickcheck
• hemoglobin photometer
• "float test" (for blood density?)

The latter one is the only one I've experienced, as well as my coworkers. However, as this discussion has pointed out to me, I'm not exactly sure what it's testing for, nor its official name. Can someone clarify what all these different tests are, how they work, what they're testing for (why they do them), etc.? Perhaps we should list them on the blood donation page with links to articles about each one? --zandperl 23:35, 12 Apr 2004 (UTC)

I'd never heard of the float test until today. (I'm pretty naive.) But it's the CuSO₄ test my link above is talking about.

It involves getting a drop of blood, and dropping it into a container of copper sulfate. The time it takes to sink to the bottom (if it does) is measured. I'd imagine the CuSO4 is at a controlled specific gravity.

I'd actually like to try it, but i don't have easy access to copper sulfate.

I can't remember much chemistry at all, but i suppose FeSO4 (or Fe₂(SO4)₃??) is a precipitate.

So does this mean it measures whole blood iron? Dunno. T 00:58, 13 Apr 2004 (UTC)

Here's two links to abstracts:

[2] Statistical analysis of inappropriate results from current Hb screening methods for blood donors.

[3] Screening for childhood anaemia using copper sulphate densitometry.

No, it doesn't measure iron in any way. The copper sulfate gravimetric screening test measures specific gravity as a way to estimate hemoglobin/hematocrit. The correlation of density with Hb/HCT is not close enough to be of use as anything but a screening test: failing it doesn't necessarily mean you're anemic. I doubt many places use it anymore: it's supposed to give a "float" result if the hemoglobin in < 12.5 g/dl, the cut-off in the U.S. for donation. (The criteria if hematocrit is measures is < 38%).

If these are listed, it probably should be at blood donation; they really don't have much to do with "phlebotomist". Of the tests Zandperl mentions:

• generic "iron test": shouldn't be listed, because it's not done. you can test serum iron, but no donation center does, or would, because the criteria for donation is the concentration of RBC's, not the amount of iron present
• hematocrit: done in some places. requires a centrifuge.
• hemoglobin quickcheck: probably a brand name for the next test
• hemoglobin photometer: a machine-read result from a chemical reaction on a testing strip. probably needs a different description, like "colorimetric hemoglobin test"
• "float test": the copper sulfate screening test: it actually measures specific gravity.
  -- Nunh-huh 01:44, 13 Apr 2004 (UTC)

Ah, that is definitely making more sense to me. Thanks so much all! I put in my understanding of what you've said in blood donation; please go and correct any misunderstandings that I put in. --zandperl 19:53, 13 Apr 2004 (UTC)