LABORATORY DIAGNOSIS

PERIPHERAL BLOOD SMEAR

PERIPHERAL BLOOD SMEAR 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

PERIPHERAL BLOOD SMEAR

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

PERIPHERAL BLOOD SMEAR Characteristics: – 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

Well-made PBS

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

Well-made PBS

PERIPHERAL BLOOD SMEAR Examples of unacceptable smears

PERIPHERAL BLOOD SMEAR Examples of unacceptable smears

PERIPHERAL BLOOD SMEAR 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

PERIPHERAL BLOOD SMEAR Optimally stained smears have the following characteristics: 1.

RBC’s should be pink to salmon in color 2. Nuclei are dark blue to purple 3. Cytoplasmic granules of neutrophils are lilac 4. Cytoplasmic granules of basophils are dark blue to black 5. Cytoplasmic granules of eosinophils are red to orange 6. The area between the cells should be clean and free of precipitated stain

PERIPHERAL BLOOD SMEAR Peripheral smear examination Correct area of blood in which to evaluate cellular distribution and perform WBC estimate

PERIPHERAL BLOOD SMEAR Peripheral smear examination “Battlement” pattern for performing a WBC differential count