Lab Investigation of The Full Blood Count and White Cell Disorders

Question 1

What is normal Haematopoiesis?

The function of RBCs?

How many types of WBCs?

What is the function of platelets?

Answer 1

• Blood cell production
• Taken from bone marrow and long bones
• Maturation occurs in BM
• Mature cells are within the peripheral blood
• RBC: stores Hb and Oxygen
• WBC: 5 types, used for infection
• Platelets: used to prevent excessive bleeding

Question 2

How long do RBCs last?

Answer 2

• RBCs last around 120 days

Question 3

Different blood tubes have different colour tops:

Purple

Rust/ Yellow

Turquoise

Black

Pink

Green

Grey

Define haemtocrit

Answer 3

Purple has EDTA in it  stops the blood from clotting. Used for FBC

Rust/Yellow  has a gel at the bottom, the clotted sample and that’s what the biochemistry samples go in. e.g. renal function

Turquoise  has citrate in it which is an anticoagulant
Important for clotting

Pink has EDTA in it  we use it for transfusion

Black for ESRs

Green has a yellow gel at the bottom, and makes cells clot to check for plasma

Grey checks for glucose

Haematocrit  percentage of the blood tube that is actually blood.

Question 4

What are these abbreviations:

Hb, Hct, MCV, MCH, RDW, reticulocyte count

Answer 4

• Hb  concentration of Haemoglobin
• Hct  Percentage of blood volume as RBC
• MCV  Mean corpuscle/cell volume. Average size of RBC
• MCH  Average haemoglobin content of RBC
• RDW  Range of deviation around RBC size
• Reticulocyte count (Reticulocyte – immature red blood cells (RBCs). In the process of erythropoiesis (red blood cell formation), reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells).
• Blood film

Question 5

What are the white blood cell differentials?

Answer 5

• Total WBC
• Neutrophils
• Lymphocytes
• Monocytes
• Basophils
• Eosinophils

Question 6

What do platelet results tell us?

Answer 6

• Platelet count and size

Question 7

Why do we need a blood film?

Answer 7

• Confirming Numbers
• Morphology – are the cells ‘normal’
• Are there cells present that shouldn’t be?

Question 8

What are the 4 rules of blood tests?

Answer 8

• All transfusion requests have to be handwritten by law
• Every sample has a laboratory number
• So, juniors can request emergency bloods
• Can process a minimum of ~1600 a day

Question 9

Define:

Anisocytosis

Polychromasia

Inclusions

Answer 9

Anisocytosis - Loads of different/unequal sizes.

Polychromasia – A disorder where there is an abnormally high number of immature red blood cells/reticulocytes found in the bloodstream as a result of being prematurely released from the bone marrow during blood formation.

Inclusions – e.g. malaria, lead poisoning, nucleus.

Question 10

How do the machines work?

Answer 10

• A plot based on light refraction and size
• Something that stains for peroxidase
o Is for the peroxidase in the neutrophils
• The machine turns the data into numbers

Question 11

When is a blood film made?

Answer 11

Blood film is made when:
• Low / high MCV
• Requested
• Warning flag

Question 12

What are the characteristics of a normal blood film?

Answer 12

• Most RBC are round
• Area/Zone of central pallor It should be approximately 1/3 the diameter of the entire red cell (cells like this are called normochromic). If it’s much larger, that means that the cell does not have enough hemoglobin (cells like this are called hypochromic) and the patient is anemic.
• Platelets are dark spots
• Neutrophil has 4 little dots
• Lymphocyte is left side dark spot