Purple-top vacutainers: uses, applications, and other considerations.

Purple-top vacutainers are blood collection tubes that contain the anticoagulant EDTA (ethylenediaminetetraacetic acid). The purple color of the stopper indicates the presence of EDTA in the tube. EDTA works by binding to calcium ions in the blood, preventing blood clotting and preserving the integrity of the blood sample for further analysis.

Some common uses and applications of purple-top vacutainers include:

1. Hematology testing: EDTA is commonly used for hematology testing, such as complete blood count (CBC) and blood cell morphology analysis. The anticoagulant properties of EDTA help prevent blood clotting and ensure accurate results.

2. Blood banking: Purple-top vacutainers are often used in blood banks for blood typing, crossmatching, and other blood compatibility testing. EDTA helps preserve the blood sample for longer periods, allowing for extended storage and testing.

3. DNA testing: EDTA is also used in DNA testing and molecular diagnostics. The anticoagulant properties of EDTA help prevent DNA degradation and ensure the integrity of the genetic material for analysis.

4. Toxicology testing: Purple-top vacutainers may be used for toxicology testing to analyze drug levels or detect the presence of toxins in the blood. EDTA helps preserve the blood sample and maintain the stability of the analytes for accurate testing.

When using purple-top vacutainers, it is important to follow proper blood collection techniques to avoid contamination or hemolysis of the sample. It is also essential to mix the blood sample gently by inverting the tube several times to ensure proper mixing of the anticoagulant with the blood.

Overall, purple-top vacutainers are versatile blood collection tubes that are commonly used in various clinical settings for a wide range of diagnostic tests. Proper handling and storage of the blood samples collected in purple-top vacutainers are crucial to ensure accurate and reliable test results.

Purple-Top Vacutainers (EDTA Vacutainers)

Purple-top vacutainers, also known as EDTA vacutainers, contain the anticoagulant ethylenediaminetetraacetic acid (EDTA). They are used to collect whole blood for hematological (blood-related) tests, such as:

- Complete blood count (CBC)
- Differential white blood cell count
- Hemoglobin
- Hematocrit
- Platelet count

Applications

Purple-top vacutainers are used in various clinical settings, including:

- Hospitals
- Outpatient clinics
- Blood banks
- Research laboratories

Other Considerations

- EDTA concentration: Vacutainers are available with different EDTA concentrations, ranging from 0.5-2.0 mg/mL. The appropriate EDTA concentration depends on the specific tests being performed.
- Sample handling: Blood samples in purple-top vacutainers must be gently mixed after collection to ensure proper anticoagulation.
- Storage: Blood samples in purple-top vacutainers should be stored at room temperature for up to 24 hours. For longer storage, they can be refrigerated at 4°C for up to 7 days.
- Sample stability: EDTA inhibits the coagulation of blood by chelating calcium ions. This can affect the stability of certain tests over time, such as platelet function assays.
- Vacuum pressure: Vacutainers come with varying levels of vacuum pressure. A higher vacuum pressure can facilitate faster blood collection, but it may also cause hemolysis (rupture of red blood cells) in some cases.
- Draw order: When collecting multiple blood samples, purple-top vacutainers should be drawn first to avoid contamination from other anticoagulants.

Advantages

- Convenient and easy to use
- Prevent blood coagulation for hematological testing
- Stable for most hematological tests

Disadvantages

- EDTA can interfere with certain tests, such as platelet function assays
- May cause hemolysis if a high vacuum pressure is used
- Limited storage stability for some tests