Evaluation of the blood smear

Question 1

Describe the examination of a blood smear on low power

Answer 1

x10, x20
Feathered edge - platelet clumps, big cells, big parasites
Body - agglutination, rouleaux (RBCs stacking)
Monolayer - RBC density, WBC numbers

Question 2

Describe the examination of a blood smear on high power

Answer 2

x40, x100
Monolayer:
- platelet numbers and morphology
- RBC morphology
- small parasites
- WBC morphology and count

Question 3

Which section of a blood smear is this?

Answer 3

Feathered edge

Question 4

Which section of a blood smear is this?

Answer 4

Monolayer

Question 5

Which section of a blood smear is this?

Answer 5

Body

Question 6

What can be analysed about RBCs at x40 or x100?

Answer 6

RBC morphology:
- anisocytosis (different sized RBCs)
- polychromasia (excess immature RBCs)
- poikilocytosis (abnormally shaped RBCs)
- inclusions (retained remnants of cellular components)

Question 7

What can be analysed about neutrophils at x40 magnification?

Answer 7

Left-shift neutrophils (immature neutrophil inflammation)
Right shift neutrophils (hypermature)
Toxic change:
- vacuolation
- blue cytoplasm
- “Dohle” bodies
- septicaemias

Question 8

What can be analysed about platelets on blood smears?

Answer 8

Number – don’t expect spontaneous haemorrhage if >8-10 platelets per oil immersion field
Size - bigger ones suggest active thrombopoiesis
Activated – may be associated with inflammation