Question 85

Venous blood from an EDTA tube should be used to ensure the best test result for a blood smear.

Using venous blood from an EDTA tube is essential for preparing an accurate blood smear, as EDTA acts as an anticoagulant that preserves the cellular components of the blood without causing distortion.

A) Venous blood from an EDTA tube

This option is correct because EDTA effectively prevents clotting, allowing for a clear and representative blood smear. It maintains the morphology of blood cells, which is crucial for accurate analysis and diagnosis.

B) Venous blood from a sodium citrate tube

While sodium citrate is also an anticoagulant, it is primarily used for coagulation studies rather than for blood smears. The use of sodium citrate may alter the shape and characteristics of blood cells, leading to inaccurate results in a blood smear.

C) Venous blood from a fluoride tube

Fluoride tubes are used primarily for glucose testing as they inhibit glycolysis. Using blood from a fluoride tube for a smear is inappropriate, as it would not preserve the cellular integrity required for morphological examination.

D) Venous blood from a heparin tube

Heparin is another type of anticoagulant; however, it can interfere with certain staining processes used in blood smear analysis. This can lead to misleading results regarding cell morphology, making it unsuitable for preparing a blood smear.

Conclusion

In summary, venous blood from an EDTA tube is the best choice for preparing a blood smear due to its ability to preserve cell morphology and prevent clotting. Other options, while they do serve specific purposes, do not provide the same level of accuracy and reliability for blood smear analysis, thus making them unsuitable for this specific test.