In which of the following areas does capillary specimen collection differ from routine venipuncture when collecting a BUN and CBC?

The correct choice for this question highlights the significance of the order of draw during specimen collection, particularly when comparing capillary specimen collection to routine venipuncture.

In routine venipuncture, the order of draw is critical to prevent contamination of the samples and to maintain the integrity of the tests being conducted. Each type of blood collection tube contains specific additives and serves a unique purpose, which requires them to be filled in a certain sequence. Failure to adhere to this order can lead to inaccurate lab results due to cross-contamination from additives in previous tubes.

In contrast, capillary specimen collection does not follow the same order of draw as venipuncture. Capillary specimens are typically obtained from a heel or finger prick, and the mixtures of blood components differ as well. When collecting from capillary sites, the blood collected is a mix of arterial, venous, and capillary blood. Thus, the order of drawing tubes from capillary specimens is often more flexible, as there are no additives that would cause the issues seen in venipuncture when collected in the wrong order.

Understanding this key difference is important for phlebotomists in ensuring accurate laboratory test results.