1. PERIPHERAL BLOOD SMEAR

2. introduction
A properly prepared blood smear is essential to accurate assessment of cellular morphology
The wedge smear is the most convenient and commonly used technique for making PBS

3. Wedge technique of making PBS
A. Correct angle to hold spreader slide
B. Blood spread across width of slide
C. Completed wedge smear

4. Characteristics are:
About two thirds to three fourths of the slide is covered by the smear
It is very rounded at featheredge (thin portion), not bullet shape
Lateral edges of the smear should be visible

5. Characteristics:
4. It is smooth without irregularities, holes, or streaks
5. When the slide is held up to light, the featheredge of the smear should have a “rainbow” appearance
6. The whole drop is picked up and spread

6. Examples of unacceptable smears are these:

7. Examples of unacceptable smears

8. Staining of PBS
Purpose of staining is to identify cells and recognize morphology easily through the microscope
Uses Wright stain or Wright-Giemsa stain which contain both eosin and methylene blue  polychrome stains

9. Optimally stained smears have the following characteristics:
RBC’s should be pink to salmon in color
Nuclei are dark blue to purple
Cytoplasmic granules of neutrophils are lilac
Cytoplasmic granules of basophils are dark blue to black
Cytoplasmic granules of eosinophils are red to orange
The area between the cells should be clean and free of precipitated stain

10. Peripheral smear examination
Correct area of blood in which to evaluate cellular distribution and perform WBC estimate

11. Peripheral smear examination
“Battlement” pattern for performing a WBC differential count