How is the order of draw determined during multiple tube collections?

The order of draw during multiple tube collections is primarily determined to prevent contamination of samples. This is crucial in achieving accurate laboratory results, as certain tests are highly sensitive to even small amounts of contaminants, which can lead to erroneous readings.

Different additives in blood collection tubes can interact with the samples. For instance, if a tube containing an anticoagulant is filled before a serum tube, traces of the anticoagulant can contaminate the serum tube, affecting the test results. Therefore, the established order of draw is designed to reduce the risk of cross-contamination between different types of tests, ensuring that each sample remains pure and suitable for analysis.

The volume of blood drawn, patient preferences, and minimizing the number of tubes used, while important considerations in practice, are secondary to maintaining the integrity of the samples through recommended procedures. Thus, the focus remains on the correct order of tube collection to safeguard the reliability of lab testing outcomes.