Lab Tube Colors on the NCLEX
Which tube for which test: red, gold, lavender, blue, green, gray.
Lab tube selection matters for accuracy. NCLEX rarely tests specifics but skills checkoffs and ATI do.
Common tubes
Red: serum, no additive. Chemistries. Gold (SST): serum separator. Most chemistries. Lavender (EDTA): CBC, blood bank. Blue (citrate): coags (PT, PTT). Green (heparin): stat chemistries, lithium level. Gray (sodium fluoride): glucose, lactate, alcohol.
Order of draw
Blood cultures → blue → red/gold → green → lavender → gray. Prevents additive carryover.
Frequently asked
Wrong tube, repeat?
Usually yes, especially for coags and CBC. Some tests can be salvaged from wrong tube.
Quick check
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