When it comes to drawing blood for various laboratory tests, it is crucial to follow the correct order of draw. The order of draw refers to the sequence of collection tubes used during venipuncture. This process ensures the accuracy and integrity of the blood samples, preventing cross-contamination and providing reliable test results. In this blog post, we will explore the correct order of draw and its significance in the medical field.

1. Yellow or Light Blue (Sterile) Tubes

The first tube in the order of draw is typically a yellow or light blue tube, which is used for sterile blood cultures. These tubes are essential for detecting and identifying any potential infections or bacteria present in the bloodstream. By drawing this tube first, it helps minimize the risk of contamination from subsequent tubes.

2. Red or Gold Tubes

The second tube is usually a red or gold tube, which is used for collecting serum or blood for various chemistry tests. These tests can provide valuable information about a patient’s organ function, electrolyte balance, and lipid levels. The red or gold tube does not contain any additives, allowing the blood to clot before further processing.

3. Light Green or Green Tubes

The third tube in the order is often a light green or green tube, known as the plasma separator tube (PST), or heparin tube. These tubes contain anticoagulants such as lithium heparin or sodium heparin, which prevent blood clotting. The green tubes are primarily used for tests requiring plasma, such as electrolyte panels and arterial blood gas (ABG) tests.

4. Lavender or Purple Tubes

The fourth tube is typically a lavender or purple tube, which contains the anticoagulant ethylenediaminetetraacetic acid (EDTA). These tubes are used for collecting whole blood or preserving the integrity of cellular components. Lavender tubes are commonly utilized in hematology tests, including complete blood counts (CBC) and blood typing.

5. Gray Tubes

The fifth tube in the order of draw is a gray tube, which contains sodium fluoride and potassium oxalate as anticoagulants. These tubes are primarily used for glucose testing, as the anticoagulants help preserve blood sugar levels. Gray tubes are crucial in diagnosing diabetes or monitoring blood glucose levels.

Conclusion

Following the correct order of draw is of utmost importance in obtaining accurate laboratory test results. By adhering to this protocol, healthcare professionals can ensure the reliability of the collected blood samples, minimize the risk of contamination, and provide appropriate patient care. Understanding the order of draw is crucial for phlebotomists, nurses, and other medical personnel involved in blood collection procedures.

We hope this article has shed light on the significance of the order of draw of blood. If you have any questions or additional insights on this topic, please feel free to leave a comment below.