1. Blood smear
A. Nada AL-Juaid

2. Definition
“A blood smear is a blood test that gives information about the number and shape of blood cells.

3. principle
a blood test used to provide information concerning drugs and diseases that affect the morphology of red and white blood cells
help diagnose certain diseases.
performed informative of all hematologic tests, allowing examination of erythrocytes, platelets, and leukocytes.

4. specimen Peripheral blood: must made immediately.
Potassium EDTA anticoagulated blood: substances that prevent blood from clotting, therefore , smear may be made from EDTA anticoagulated blood as long as 2 -3 hours after collection.
All specimen must be free of clots.

5. Preparation of Peripheral Blood Smear
1. Placing a small drop of venous blood on a glass microscope slide, using a glass capillary pipette.

6. Preparation of Peripheral Blood Smear
2. A spreader slide has been positioned at an angle and slowly drawn toward the drop of blood.

7. Preparation of Peripheral Blood Smear
Step 3. The spreader slide has been brought in contact with the drop of blood and is being drawn away. Note layer of blood at the edge of the spreader slide.

8. Preparation of Peripheral Blood Smear
Step 4. The spreader slide is further pulled out, leaving a thin layer of blood behind.

9. Preparation of Peripheral Blood Smear
Step 5. The blood smear is nearly complete.

10. Preparation of Peripheral Blood Smear
Step 6. End result. A glass slide with a well-formed blood film. After drying for about 10 minutes, the slide can be stained manually or placed on an automated slide stainer.

11. Preparation of Peripheral Blood Smear
Frosted edge: it is the space for label the smear with patient’s last name, first name, speciment number and date.

13. Staine use
Lishment stain: by using the automated Hema-Tek II Slide Stainer
Hema-Tek 2000 stainer

14. Automated method
The air-dried smear is fixed with absolute methanol and placed on staining rack.
Allow slide to dry completely.
Prime stainer lines to remove air bubbles.
Place dried smear on stainer.

15. stained manually
fixed :Air dry the thin smear for 10 minutes. After drying, the thin smear should be fixed in methanol. This can be done by either dipping the thin smear into methanol for 5 seconds or by dabbing the thin smear with a methanol-soaked cotton ball
Leishman's stain:
 Add 7-8 drops of the stain and leave for 1-2 minutes.
Then add drops of buffered distilled water, mix thoroughly,
leave for minutes.
Then wash off with clean water, drain, dry and examine.

16. Characteristics of a good smear
Thick at one end, thinning out to a smooth rounded feather edge.
Should occupy 2/3 of the total slide area.
Should not touch any edge of the slide.
Should be margin free, except for point of application .

17. Adjustment of the smear length
Increasing the angle of the spreader slide will decrease the length of the smear.
decreasing the angle will increase the smear length.

18. References
tek-2000-stainer-storage-of.html
pages/hematopath/pbs.html
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