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Blood sample preparation

Materials needed

  • Glass microscope slides
  • Plain capillary tube or other device for transferring blood from tube to slide

Slide preparation

  • Gently mix blood by slowly inverting the EDTA tube 5-8 times.
  • Place clean glass slide on a flat surface. If a glass slide with a frosted end is used, place the frosted end facing upward closest to your dominant hand.
  • Label the slide with patient name or other identifying information.
  • Place a small drop of blood on the slide about 1 cm from the frosted area near the middle of the slide.
  • Firmly hold glass slide containing the drop of blood by the edges between thumb and forefinger of NON-dominant hand.
  • Hold a second (spreader) slide by the edges between thumb and forefinger of your dominant hand.
  • Place front edge of spreader slide against the surface of the specimen slide, slightly in front of blood drop and a 30-45 degree angle.
Spreader Position
  • Draw the spreader slide back through the drop of blood. As soon as contact is made with the blood, the drop will spread rapidly toward the outer edges of the spreader slide.
  • Maintaining the proper angle and applying little to no pressure, move the spreader slide forward with a smooth and rapid motion over the entire length of the specimen slide to make the smear.
  • The appearance of the blood smear should have a thick body (near the point of origin where the blood drop was made) and a thinner monolayer with a very thin edge ("feathered edge").
Feathered Edge
  • Allow the slide to dry completely (either air dry or with a fan).