Question 63

Citrate, heparin, EDTA, fluoride

The correct order of collection for blood samples is citrate, heparin, EDTA, and fluoride. This sequence is important to prevent contamination and ensure accurate test results.

A) Citrate, heparin, EDTA, fluoride

This option is correct as it follows the standard order of draw. Citrate is collected first to prevent clotting, followed by heparin, then EDTA, and finally fluoride, which is used for glucose testing. This order helps minimize potential cross-contamination of additives that can interfere with test results.

B) Citrate, EDTA, heparin, fluoride

This option is incorrect because it places EDTA before heparin. According to the standard order of collection, heparin should be collected after citrate but before EDTA to avoid any potential interactions that could affect coagulation tests.

C) Fluoride, EDTA, heparin, citrate

This option is also incorrect as it places fluoride before citrate and heparin. The inclusion of fluoride in the blood collection process should occur last, as it is specifically used to preserve glucose levels, and collecting it earlier could compromise the results of other tests.

D) Fluoride, heparin, EDTA, citrate

This option is incorrect for the same reason as option C. Fluoride should not be collected before any other anticoagulants, and placing it first could lead to inaccurate test results due to its preservative properties affecting other components in the sample.

Conclusion

The correct order of collection is crucial for accurate laboratory results, and option A adheres to this standard. All other options disrupt the sequence, leading to potential errors in test outcomes due to additive interactions. Proper adherence to the order of draw is essential for maintaining the integrity of blood samples.