Question

In the context of the tubes you mentioned (lavender, light blue, red, green), the general order of draw is as follows:

1. **Light Blue:** This tube typically contains an anticoagulant called sodium citrate and is used for coagulation studies, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT).

2. **Red:** The red tube does not contain anticoagulants and is used for various chemistry tests, including serum chemistry panels and blood bank (serology) testing.

3. **Green:** The green tube contains heparin or other anticoagulants and is used for tests that require plasma, such as blood gas analysis and some chemistry tests.

4. **Lavender:** The lavender tube contains the anticoagulant ethylenediaminetetraacetic acid (EDTA) and is typically used for complete blood count (CBC) and blood cell morphology studies.

Answer 1

Anticoagulants in blood collection tubes, such as sodium citrate, heparin, and EDTA, prevent coagulation and are selected based on the diagnostic test required. The order of draw is essential to ensure accurate test results.

Step-by-step explanation:

The student's question pertains to the order of draw in phlebotomy and the various types of anticoagulants used in different blood collection tubes. Anticoagulants are substances that prevent blood coagulation, ensuring that blood samples can be effectively analyzed for various medical tests. The light blue tube containing sodium citrate is utilized for coagulation studies as it inhibits calcium, which is necessary for the coagulation cascade. Red tubes, lacking anticoagulants, are meant for serum chemistry tests. Green tubes with heparin, an anticoagulant, are used for plasma-based tests such as blood gas analysis. Lastly, lavender tubes contain EDTA, which acts as an anticoagulant by binding calcium, and are typically used for complete blood count (CBC) and blood morphology studies. This highlights the importance of correct order of draw and the utilization of specific anticoagulants for varying diagnostic purposes.