ASCP (American Society for Clinical Pathology) Phlebotomy Technician Certification Practice Exam

The characteristic of a feathered edge in a blood smear that indicates proper technique is when it narrows to a thin layer. This aspect is critical for evaluating blood cells effectively. A well-prepared feathered edge allows for the optimal distribution of cells, ensuring that they are thinly spread out. This thin layer is essential for accurate microscopic examination, as it helps in identifying the morphology of different cell types without overlaps, which can obscure details and lead to misinterpretation.

In a properly made smear, the transition from a thicker area to the feathered edge should be smooth, allowing for a gradual spread of cells. Observing this thinness helps phlebotomists and laboratory technicians assess the sample's quality, ensuring that there is adequate separation of cells to identify abnormalities or diagnose conditions accurately. A feathered edge that is too thick or shows clumping can hinder this assessment. Hence, a narrow layer is a clear indicator of proper technique in creating a blood smear.