Laboratory Investigation of the Full Blood Count

Question 1

What does a full blood count (FBC) show?

Answer 1

Erythrocytes:

• Hb: concentration of Haemoglobin
• Hct: Percentage of blood volume as RBC
• MCV: Average size of RBC
• MCH: Average haemoglobin content of RBC
• RDW: Range of deviation around RBC size
• Reticulocyte count
• Blood film

Leukocytes

• Total leukocytes
• Differential neutrophils, lymphocytes, monocytes, basophils, eosinophils

Platelets

Question 2

What does a blood film show?

Answer 2

• Morphology - are the cells normal?
• Are there cells present that shouldn’t be?
• RBCs - size, colour, shape, polychromasia, inclusions.
• WBCs - numbers, dysplastic morphology, immature cells, abnormal cells (blasts, atypical lymphoid cells), inclusions.