Question 85

Venous blood from an EDTA tube ensures the best test result for a blood smear.

Using venous blood from an EDTA tube is essential for preparing a blood smear, as EDTA acts as an anticoagulant that preserves the cellular components of the blood for accurate microscopic examination.

A) Venous blood from an EDTA tube

This option is correct because EDTA is the preferred anticoagulant for blood smears. It effectively prevents clotting, which is crucial for obtaining a representative sample of the blood's cellular components, allowing for precise analysis.

B) Venous blood from a sodium citrate tube

Sodium citrate is not ideal for blood smears, as it is primarily used for coagulation studies. While it does act as an anticoagulant, it may alter the morphology of blood cells and is not suited for accurate cellular evaluation in a smear.

C) Venous blood from a fluoride tube

Fluoride tubes are specifically designed for glucose preservation and are not suitable for blood smears. The presence of fluoride can interfere with the staining process and the assessment of blood cell morphology, leading to inaccurate results.

D) Venous blood from a heparin tube

Heparin can also act as an anticoagulant, but it is not optimal for blood smears. Heparin may cause changes in blood cell morphology and lead to difficulties in staining, which affects the quality of the smear.

Conclusion

In summary, venous blood from an EDTA tube is the only option that supports the accurate preparation of a blood smear by preserving cell morphology and preventing clotting. All other options either interfere with the smear process or are intended for different types of tests, making them unsuitable for this specific purpose.