Preparation of Blood Smear

Examining a peripheral dry blood smear under the microscope is an important, simple laboratory test because it lets a technician estimate the approximate number of the different cellular components of blood, study their shape and appearance (morphology), spot any blood parasites present, and observe how the body's blood cells are responding to disease. To prepare a smear, a small drop of blood is placed about 1 cm from one end of a clean glass slide; a second glass slide is held against the first at roughly a 45-degree angle and drawn back just enough to touch the drop, letting the blood spread along its edge by capillary action; the second slide is then pushed forward in a single smooth, quick stroke, dragging the blood out into a thin film across the first slide. The resulting film is stained - using Leishman's stain in this technique - then left to dry and rinsed of excess stain before being examined under a light microscope. A well-made, well-stained smear …