5. Lab Investigations of the FBC

Question 1

What is FBC? and what do the results show?

Answer 1

• Full blood count
• RED BLOOD CELL RESULTS
• 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
• WHITE BLOOD CELL RESULTS
  Total WBC and differential
  Neutrophils, lymphocytes, monocytes,
  basophils, eosinophils
• PLATELET RESULTS
  Platelet count and size
• OTHERS: WARNING FLAGS

Question 2

What does a blood film show?

Answer 2

1. Confirms numbers
2. Morphology - are the cells ‘normal’.
3. Are there cells present that shouldn’t be?

• Red cells: size, colour (Hb content), shape (round, TDP, irregular, elliptocytes - poikylocytosis), polychromasia (residual RNA and bigger than RBCs) and inclusions
• White cells: numbers, normal morphology, immature cells (myelocytes and precursors), abnormal cells (blasts, atypical lymphoid cells) and inclusions

Question 3

Define poikylocytosis and anisocytosis.

Answer 3

• Poikylocytosis – lots of different shapes

- Anisocytosis – lots of different sizes

Question 4

What are the meaning of the different coloured lids of the blood test tube?

Answer 4

• Purple (lavender) = whole blood analysis e.g. FBC, ESR and blood film. Contains EDTA (anticoagulant by binding to calcium in the blood)
• Pink = For whole blood samples sent to the transfusion lab e.g. for group and save, and crossmatch. Contains EDTA
• Blue = For tests that involve the clotting system – requires inactivated whole blood for analysis. E.g. D-dimer, coagulation screen
• Yellow (gold) = contains serum separator and clot activator. E.g. U+E, CRP
• Grey = glucose and lactate
• Red = clot activators
• Dark green = anticoagulant. E.g. for ammonia and insulin
• Light green = anticoagulant and plasma separator gel.

Question 5

UPDATE THIS: How is the plot distributed?

Answer 5

According to light refractions and size.