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Lab Procedure: Wright’s Stain Using Cameco Quik Stain
18D Skills and Training ManualWhen: You are performing a complete blood count (CBC).
What You Need: A properly collected blood sample, Wright’s stain (Cameco Quik Stain), glass slides,
capillary tubes, a staining rack, distilled water, a microscope, immersion oil, 95% methanol and a laboratory
request form.
What To Do:
- Prepare the glass slides by cleaning them in 95% methanol.
- Prepare the blood smear.
a. Place a drop at a point midway between the sides of the slide and a short distance from one end.
b. Place the edge of the spreader slide on the specimen slide at a 30° angle.
c. Pull the spreader slide toward the drop of blood until contact is made.
d. Push the spreader slide toward the opposite end of the specimen slide, drawing the blood behind
it into a thin film.
e. Allow the smear to air-dry. The smear should have three areas represented.
(1) The thick area has:
(a) An increase of smaller cells with rouleaux formation.
(b) Poor cellular characteristics.
(2) The thin area has:
(a) An area of choice for reading a differential.
(b) Cellular characteristics which are at their best.
(c) RBCs that are touching without overlapping.
(3) The feathered edge has:
(a) An increase in larger cells.
(b) Cellular distortion with gaps between the RBCs. - Write the name or identification number of the patient with a lead pencil in the thick area of the smear
or on the frosted end of the slide. - Stain the slide.
NOTE: For best results, blood smears should be stained within 2 hours after they are prepared.
a. Fix the smear and let it air-dry.
b. Cover the slide with Wright’s stain and allow it to remain on the smear for 5 to 10 seconds. The
Wright’s stain is polychromatic; dyes in the stain will produce multiple colors when applied to cells.
The stain is composed of two main parts, Methylene-blue and eosin.
(1) Methylene-blue is an alkaline dye that has an affinity for the acidic portions of the cell--DNA in the
nucleus and RNA in the cytoplasm. It stains varying shades of blue to purple.
(2) Eosin is the acidic portion of the dye that has an affinity for the basic portions of the cell. It stains
in varying shades from orange to pink.
NOTE: The stain should cover the slide but should not be allowed to overflow the edges. A blue-green
metallic sheen should be on the surface. The exact time that the stain is applied may vary with each
batch of stain.
c. Rinse the slide thoroughly with distilled water for 15 to 20 seconds.
d. Wipe the stain from under the slide and allow it to air-dry. - Examine the smear under the oil immersion objective.
- Recognize discrepancies with staining and the way to correct those discrepancies.
a. For darker stained leukocytes, dip the slide in distilled water for 1 minute or more after staining.
b. For lighter stained leukocytes, decrease the Wright’s stain time. - Insure that the staining reactions are sufficient.
a. RBCs appear buff pink to orange.
b. WBCs have a blue nucleus with a lighter stained cytoplasm.