What is the main reason for collecting specimens in specific order during venipuncture?

The primary reason for collecting specimens in a specific order during venipuncture is to prevent cross-contamination of additives from different tubes. When blood is drawn, various collection tubes contain specific additives designed to preserve or enhance certain blood components for analysis. If blood is collected in the wrong order, the additives from one tube can contaminate the contents of another, potentially leading to inaccurate results in laboratory tests. For instance, if a tube containing an anticoagulant is filled before a serum tube, the anticoagulant could interfere with tests that require serum by preventing clot formation. Therefore, following the established order of draw is critical to ensuring the integrity and accuracy of the collected specimens.