When performing capillary puncture, what is the recommended order of draw according to CLSI?

The recommended order of draw when performing capillary punctures according to CLSI guidelines is indeed to collect blood gas specimens first, followed by EDTA specimens, and then serum specimens. This sequence is crucial for preventing cross-contamination between different types of tests, which could potentially alter the results.

Blood gas specimens are particularly sensitive and should be collected first to ensure the integrity of the gases being measured, as they can be affected by air exposure and other factors. Following this, EDTA specimens come next; EDTA is an anticoagulant that helps preserve the cellular components of the blood for tests that require whole blood or plasma analysis. Lastly, serum specimens are collected. These typically require clotting to occur first, making it important to collect them after the other specimens.

Using this order ensures that the properties of each sample type are maintained and that test results are reliable, reflecting the true composition of the blood without interference from additives or contaminants that might reside in the collection tubes used for different specimen types.