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Saturday, February 7, 2015

Correct Order of Blood Draws

Blood draw, blood, labs, nursing, phlebotomy, medical, nursing school, nursing student, nurse, RN

This seemed to be one of those things that fell through the cracks during nursing school. What order do we draw our blood labs? Why does it matter? What tubes are used for which tests? Should I shake the tube once it is filled?


Ok. From talking to others, I don't think any of us are taught this in school. But if you were, then your school freaking rocks!! Whoo Hoo!

Why Does it Matter What Order I Draw My Labs?

It matters because some of these test tubes have additives in them that will screw up the results of the blood in the lab. You want your blood cultures to be first because you don't want to run a risk of contaminating it with additives from other tubes. 

For instance you don't want to draw an EDTA tube (light purple) and then go to draw your coagulation tubes (light blue). The EDTA tube might have left some residual substance and will prevent the blood from clotting, which is bad if you drew your coagulation tubes after. Now they won't clot. You'll either have to draw another set of labs, or they give false results and we treat them based off of these false results. 

No bueno.

Also, grey tubes must be kept on ice. So having them last is nice so that your ice doesn't melt. 

ABG's also need to be put on ice immediately.

What Tubes are Used for What Tests?

I'm still learning this (which is why I'm writing this post!) 

The above chart covers this quite well. I don't have too much to add. 

Your glass containers are used for blood cultures. You need two blood cultures from EACH side of the patient for a total of FOUR bottles total. Sometimes you can only get one set of cultures when the patient is agitated, and that's okay. Don't feel bad. Let them rest for a bit and calm down.

Red- there's no additives. This is used for lipid panels, electrolytes, hepatic function, Digoxin, HCG (you make this during pregnancy. I'm not talking about that idiotic fad diet. Yes, it is idiotic. Don't do it.) I also use this tube as my discard tube as well.

Should I Shake My Tubes?

Yes, for the most part. By "shake" I really mean, nicely, and slowly invert the tube a few times. About 8 times, for tubes EXCEPT LIGHT BLUE.

DO NOT mix light blue. 

The reason to shake these test tubes is to mix whatever additive is in it with the blood. If it's an EDTA (lavender) tube then you don't want the blood to clot, so it needs to be thoroughly mixed with the EDTA (which stands for Ethylenediaminetertraacetic acid.) Now you know why I've been leaving it to EDTA this whole post. Wow! That's a mouthful!
-- That's what she said.

Did you learn the correct order to draw labs in nursing school? Does your institution have a chart hanging up to identify the correct order to draw blood labs? Leave a comment below!!




  1. Love the infographic - shared it and your blog with our Veterinary Technicians on our VetTechLife Facebook page ( I also want to let you know that there are several typos (e.g., Fluoride Oxalate & blood glucose).

    1. Personally, I like bloog glucose better.

  2. You need to know that the light blue tube(sodium citrate) does not clot. You do not want it to clot. It is also not a good idea to use the word shake when speaking about the of mixing tubes. The word invert gently should be used as you want to avoid hemolysis. I have been a phlebotomist for almost 26 years and would give this advice to you.

  3. I'm sorry, I also forgot to mention that the light blue tube does need inverted gently to mix the sodium citrate.

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  5. This is a great resource for the order of draw. I also recommend checking out The Order of draw explained it includes some additional information on how to remember the order.