Question

According to CLSI/NCCLS, what is the correct order of draw using the evacuated tube system?

1) Green top, Lavender top, Blue top, Red top, Gray top
2) Gray top, Red top, Blue top, Lavender top, Green top
3) Green top, Gray top, Lavender top, Blue top, Red top
4) Blue top, Lavender top, Red top, Gray top, Green top

Answer 1

The correct order of draw using the evacuated tube system as per CLSI guidelines is: Blue top, Red top, Green top, Lavender top, and Gray top.

Step-by-step explanation:

The correct order of draw using the evacuated tube system according to the Clinical and Laboratory Standards Institute (CLSI), which was previously known as the National Committee for Clinical Laboratory Standards (NCCLS), is as follows:

1. Blue top tube - for coagulation tests, contains sodium citrate.
2. Red top tube - for serum determinations, may contain a clot activator.
3. Green top tube - contains heparin, used for plasma determinations.
4. Lavender top tube - contains EDTA, used for hematology tests such as complete blood count (CBC).
5. Gray top tube - typically contains sodium fluoride and potassium oxalate, used for glucose determinations and to preserve blood for alcohol testing.

Adhering to the correct order of draw is essential to prevent cross-contamination between different additives used in blood collection tubes which could affect the results of patient tests.