What is the significance of the sequence of blood collection?

The sequence of blood collection is crucial because it ensures no contamination of specimens, which is vital for accurate laboratory results. Each type of additive in collection tubes can interfere with others if not drawn in the correct order. For instance, if a tube with an anticoagulant is filled before a tube destined for serum testing, the anticoagulant may contaminate the serum sample, leading to erroneous test results. By adhering to the proper order of draw, healthcare professionals minimize the risk of cross-contamination and ensure that the samples provide reliable data for diagnostic purposes. This is particularly important in cases where precise measurements are needed, such as in tests for blood cultures, coagulation studies, and various biochemical analyses.