GH practicals

Question 1

Why do we set up the microscopes in kohler illumination?

Answer 1

• provides contrast w/ little to none atrefacts

- focus light on sample & not have it scattered

Question 2

Why can MCH & MCHC be useful in classification of anaemia?

Answer 2

• if MCH & MCHC values are low that usually indicates low amounts of Hb = anaemia
• If MCH & MCHC values are normal that means anemia is not due to low levels of Hb but other factors like folate deficiency = macrocytic

Question 3

What’s the anticoagulant used for full blood counts? WHy?

Answer 3

EDTA

- binds to divalent cations like Ca2+ (Factor IV) - which is necessary for coagulation

Question 4

what makes a good blood film?

Answer 4

• monolayer ie. RBC not overlap & not too far from each other
• no holes
• flat film &a smooth appearance
• no clear streaks
• good length
• straight edges
• labeled
• no excess dpx

Question 5

Components of romanowsky stain & mechanism of staining

Answer 5

1. methylene blue (oxidation products like azure B) binds to acidic groups = blue nucleus
2. Eosin Y (or B) binds to alkaline groups = red cytoplasm

Question 6

Why are white cell differentials in absolute numbers and not relative?

Answer 6

bc relative (%) no. can be misleading; % may be within normal range but out of range for absolute no.

Question 7

Why is a reticulocyte count useful for laboratory tests for monitoring anaemia?

Answer 7

high reticulocytes indicate inc. production of RBC (= can indicate if treatment is working)

Question 8

morphological name for sickle shaped RBC

Answer 8

depranocyte

Question 9

WHat is “flagging” in terms of automated analysers? e.g.

Answer 9

flags abnormalities in blood sample or problems in the machine - technical or pathological significance
e.g. IG (immature granulocyte) flag, blast flag, anisocytosis

Question 10

What is a howell jolly body and what does this indicate

Answer 10

basophilic dot inside a RBC = left over remnant in the RBC that should’ve been removed in the spleen, but it’s presence indicates poor splenic function

Question 11

What is a heinz and what does this indicate

Answer 11

denatured Hb as a result of oxidative damage

Question 12

stages of iron deficiency anaemia

Answer 12

1. iron storage in muscle & liver deplete
2. iron storage fully depleted but Hb levels in blood are normal
3. ferritin levels dec. = affect how iron is stored = iron supply is insufficient to maintain normal Hb concentration

Question 13

what causes pernicious anaemia?

Answer 13

impaired uptake of Vit. B12 bc stomach lining is not producing enough intrinsic factor = not able to absorb Vit B12

Question 14

Discuss why is it necessary to observe universal safety precautions when handling blood samples?

Answer 14

minimise the risk of getting any diseases from blood samples

- by treating them with caution as if they carry a disease