peripheral blood smear
Meaning of peripheral blood smear: This test spreads a thin layer of blood on a slide so a technologist can examine the shape and appearance of individual blood cells directly.
Definition of peripheral blood smear
A peripheral blood smear is a laboratory test in which a small drop of blood is spread thinly across a glass slide, stained, and then examined directly under a microscope. Unlike tests that simply count blood cells, a smear allows a trained observer to assess the size, shape, and appearance of individual red blood cells, white blood cells, and platelets.
The peripheral blood smear can reveal abnormalities not captured by a cell count alone, such as red blood cells with an abnormal shape, immature white blood cells that should not normally be circulating, or the presence of an infectious organism visible within or alongside blood cells.
A peripheral blood smear is often performed alongside a complete blood count, since the count provides quantitative numbers for each cell type while the smear adds a direct visual assessment of how those cells actually appear.
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Used in a sentence
A peripheral blood smear was reviewed after the complete blood count showed an unexpected abnormality.
Good to know
A complete blood count reports how many of each blood cell type are present, while a peripheral blood smear shows how those cells actually look, and the two tests are often used together because each provides information the other cannot.