Difficulty: Medium

Average Score: 50%

When a serum separation tube (SST) is collected, which of the following actions should the phlebotomist take to ensure optimal test results?

Rationale

Invert the tube 5 to 8 times and then set for 30 min prior to centrifugation.

Inverting the serum separation tube (SST) 5 to 8 times ensures adequate mixing of the serum with the clot activator, promoting optimal coagulation. Allowing the tube to sit for 30 minutes before centrifugation also facilitates proper serum separation, which is crucial for accurate test results.

A (Invert the tube 5 to 8 × and then set for 30 min prior to centrifugation.) CORRECT

This option correctly describes the recommended procedure for handling an SST. Inverting the tube the specified number of times ensures thorough mixing, while the 30-minute wait allows sufficient time for clot formation and separation of serum from the cellular components.

B (Invert the tube 1 to 3 × and then set for 1 hr prior to centrifugation.) YOUR ANSWER

Inverting the tube only 1 to 3 times may not provide adequate mixing of the clot activator with the blood, potentially leading to incomplete clot formation. Additionally, a 1-hour wait is excessive and may affect the quality of the serum separated, which can compromise test results.

C (Invert the tube 2 to 4 × and then set for 15 min prior to centrifugation.) YOUR ANSWER

While inverting the tube 2 to 4 times provides some mixing, it is insufficient to ensure optimal coagulation. The 15-minute waiting period is also too short, as it may not allow enough time for complete clot formation, which is essential for accurate serum separation.

D (Invert the tube 8 to 10 × and then set for 2 hr prior to centrifugation.) YOUR ANSWER

Although inverting the tube 8 to 10 times ensures good mixing, waiting for 2 hours is unnecessary and could lead to degradation of the sample or changes in analyte concentrations, further impacting test accuracy.

Conclusion

Proper handling of serum separation tubes is critical for ensuring accurate laboratory results. Inverting the tube 5 to 8 times and allowing it to sit for 30 minutes before centrifugation strikes the right balance between effective mixing and sufficient clotting time. Deviating from these guidelines can compromise the integrity of the serum and lead to unreliable test outcomes.

Related Questions

View all