Page 298 - parasitology for medical and clinical laboratoryprofessionals

278 CHAPTER 12

PROCEDURE 12-5

(continued)

Delmar/Cengage Learning

FIGURE 12-10 Demonstration of two methods of preparing thick blood smears, directly
from finger puncture and triangular pattern of blood on slide

Delmar/Cengage Learning

FIGURE 12-11 Image of both thin- and thick-stained blood smears on same slide

Staining the Thin Smears
1. For thin smears, place a drop of blood on a slide, and, using another slide,
streak out the blood as in making a differen tial smear. It is important to use a
technique that will result in a good feathered edge. Allow to air-dry.
2. When staining the thin smear, it is advantageous to have a positive control slide
that is stained with all malaria specimens when available.

3. Dip the thin slide in a Coplin jar of Absolute Methanol five times, 1 second per dip.
4. Place the slide in a Coplin jar of Wright-Giemsa Stain (Quick-Stain) for 10 seconds.
5. Place slide in a Coplin jar of distilled water for 20 seconds or more to effect a more
desired color balance. This may take practice and experience to perfect this step.
6. Drain the slide and allow to air-dry in an upright position, by standing the slide
on its end. There are special racks available for this step.
Staining the Thick Smears
1. Place slide on a flat surface, such as a rack over a sink.

2. Carefully overlay the entire slide with distilled water.