CPT (Certified Phlebotomy Technician) Practice Exam

Blood smears need what kind of edge?

1. Circular

2. Feathered

3. Squared

4. Smooth

The correct answer is: Feathered

The correct choice is the feathered edge because blood smears are prepared to allow for optimal microscopic examination of blood cells. A feathered edge is created by spreading the drop of blood thinly across the slide so that the cells are dispersed in a manner that allows for individual identification. In this technique, the blood sample is spread at an angle, which helps to create a more uniform layer of cells, with some areas having a dense concentration and others being less concentrated, hence forming a feathered edge. This specific preparation is essential for hematological analysis, as it enhances the visualization of different types of cells and their morphology, which is crucial for accurate diagnoses. Other options do not provide the appropriate structure needed for effective microscopic analysis. For example, a circular edge would not create the necessary thin smear required for detailed examination of blood components. A squared edge misses the correct angle spread necessary for the dispersion of cells. A smooth edge does not achieve the variances in density that a feathered edge does, which is important for both identifying abnormalities and counting cells accurately.