Art and Science of Laboratory Medicine

Art and Science of Laboratory Medicine

Sunday, March 23, 2014

How to Prepare a Perfect Peripheral Blood Smear?

A peripheral blood smear (peripheral blood film) is a glass microscope slide coated on one side with a thin layer of venous blood. The slide is stained with a dye, usually Wright’s stain, and examined under a microscope.

Peripheral Blood Smear Preparation

The wedge slide ("push slide") technique developed by Maxwell Wintrobe remains the standard method for the preparation of peripheral blood smears (films). The following procedure is utilized to prepare a peripheral smear.
  1. Place a 1" x 3" glass microscope slide with a frosted end on a flat surface (usually the counter top of a laboratory bench).
  2. Attach a label on the slide or write the patient name, specimen identification number, and date of preparation on the frosted surface.
  3. Place a 2 - 3 mm drop of blood approximately 1/4" from the frosted slide, using a wooden applicator stick or glass capillary tube.
  4. Hold the slide by the narrow side between the thumb and forefinger of one hand at the end farthest from the frosted end.
  5. Grasp a second slide ("spreader slide") between the thumb and forefinger of the other hand at the frosted end.
  6. Place the edge of the spreader slide on the lower slide in front of the drop of blood (side farthest from the frosted end).
  7. Pull the spreader slide toward the frosted end until it touches the drop of blood. Permit the blood to spread by capillary motion until it almost reaches the edges of the spreader slide.
  8. Push the spreader slide forward at a 30o angle with a rapid, even motion. Let the weight of the slide do the work. 
Watch the images and read more:
Peripheral Blood Smear Evaluation

Source: Medical College of Virginia, Virginia Commonwealth University Richmond
Image crEdits: Wikimedia

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