Blood Smear Examination

A blood smear examination (peripheral blood smear) is a lab test where a thin layer of blood is spread on a glass slide, stained, and observed under a microscope. It helps diagnose anemia, infections, leukemia, malaria, and other blood disorders.

Procedure

Sample Collection

• Specimen: Fresh capillary or venous blood.
• Anticoagulant: EDTA (for venous blood).
• Timing: Prepare smear within 2 hours.
• Capillary sample: Usually from a finger prick.

Smear Preparation

1. Place a small drop of blood 1 cm from one end of the slide.
2. Hold a spreader at 30–45°, pull back to touch the drop, then push forward smoothly to make a thin film with a feathered edge.
3. Air dry completely.

Staining (Leishman’s Stain)

• Fixation: Flood with Leishman stain for 2 min (methanol fixes cells).
• Staining: Add double volume of buffered water (pH 6.8) and stain for 8–10 min.
• Washing: Rinse gently with buffered water.