What common mistake can occur during the collection of blood samples?

Failing to rotate the collection tube is indeed a common mistake that can occur during the collection of blood samples. When blood is drawn into a collection tube, it is essential to mix the blood with any additives or anticoagulants contained in the tube. Rotating or gently inverting the tube allows for proper mixing, which is critical for ensuring that the sample remains homogeneous and that the additives are effective. If this step is neglected, it can lead to false test results, such as inaccurate coagulation profiles or erroneous laboratory findings, due to clumping or altered properties of the blood sample.

The other options do not present the same level of risk for collecting a viable blood sample. Using a sterile container is standard practice to prevent contamination, collecting from an established vein is generally a desired approach, and pre-labeling the collection tube aids in efficient specimen management.