25-10: Wright Stain—Thin Smear for Malaria

Uses

To evaluate for the presence of ring trophozoites.

Materials

Air-dried blood smear, Coplin jar of Wright stain, slide rack, pH 7.2 buffer, and blotting paper.

Method

1. Place a drop of blood on the middle of a slide.

2. Hold another slide evenly on top of the slide at a 45-degree angle and drag the slide over the drop of blood to the opposite edge to spread the blood evenly.

3. Allow the blood to dry for 5 to 10 minutes.

4. Stain air-dried smears in a closed Coplin jar of Wright stain for 5 minutes.

5. Place the slide on a rack.

6. Rinse and treat with pH 7.2 buffer primed with 1 mL Wright stain per 400 mL for 3 minutes.

7. Rinse in pH 7.2 buffer for 20 seconds.

8. Blot dry and mount on microscope at ×100 (oil immersion).