Why do we twirl and tap the blood in the collection tube after a puncture?

The purpose of twirling and tapping the blood collection tube after a puncture is primarily to ensure that no clots form in the sample. When blood is drawn into a collection tube, especially one that contains an anticoagulant, it is crucial to facilitate the mixing of the blood with the anticoagulant effectively. This mixing action helps to prevent the blood from clotting, which could compromise the integrity of the sample and affect the accuracy of subsequent laboratory tests.

By thoroughly mixing the blood and the anticoagulant through gentle twirling or tapping, the risk of clot formation is significantly reduced, enabling more reliable test results. This is particularly important for tests that require whole blood or plasma, as clots can interfere with the analysis and lead to erroneous interpretations of the results.