A spray-dried K2EDTA tube meant for 3 mL of blood receives only 1 mL. How are the spun PCV and the calculated MCHC affected?

PCV falsely low, MCHC falsely high

PCV falsely low, MCHC falsely low

Neither is affected by the excess EDTA

PCV falsely high, MCHC falsely low

Coarse basophilic stippling of red cells in a battery-factory worker with abdominal colic is due to aggregates of:

Ribosomes, from impaired RNA breakdown

Denatured haemoglobin, from oxidant injury

Iron granules, from blocked haem synthesis

Nuclear DNA, from defective nuclear expulsion

Which cells produce most of the body's erythropoietin?

Peritubular interstitial cells of the kidney

Juxtaglomerular cells of the kidney

Stromal macrophages of the marrow

Hepatocytes around the central veins

Haematopoiesis, cell counts and blood films

32 Kerala MSc MLT Entrance practice questions on Haematopoiesis, cell counts and blood films, part of Haematology and Blood Banking. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A spray-dried K2EDTA tube meant for 3 mL of blood receives only 1 mL. How are the spun PCV and the calculated MCHC affected?
1. APCV falsely low, MCHC falsely low
2. BNeither is affected by the excess EDTA
3. CPCV falsely high, MCHC falsely low
4. DPCV falsely low, MCHC falsely high
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Answer: D · PCV falsely low, MCHC falsely high
Excess EDTA makes the plasma hypertonic, so water leaves the red cells and they shrink. The centrifuged PCV therefore falls, and since haemoglobin is unchanged, the MCHC (Hb divided by PCV) rises falsely. ICSH recommends about 1.5 mg of EDTA per mL of blood, which is why tubes must be filled to the mark. Excess EDTA also distorts red cell and leucocyte morphology on the film.
- A: MCHC rises, not falls, when the PCV falls with an unchanged haemoglobin.
- B: A threefold excess of EDTA is enough to shrink the cells measurably.
- C: Shrunken cells pack into a smaller volume, so the PCV cannot rise.
Question 2 · Hard
A 24-year-old woman with jaundice and splenomegaly has a reticulocyte count of 9% and a PCV of 30%. Taking a normal PCV of 45% and a maturation time of 2 days at this PCV, what is her reticulocyte production index?
1. A3.0
2. B6.75
3. C6.0
4. D4.5
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Answer: A · 3.0
First correct the count for anaemia: 9% x 30/45 = 6.0%. Then divide by the maturation time, because reticulocytes released early under EPO stimulation stay longer in the circulation: 6.0 / 2 = 3.0. An RPI above 2 shows an effective marrow response, as expected in haemolysis. Dividing 9% by 2 without the PCV correction gives 4.5, stopping after the first step gives 6.0, and inverting the PCV ratio gives 6.75.
- B: 6.75 comes from inverting the PCV ratio (45/30).
- C: 6.0 is the corrected count, before dividing by the maturation time.
- D: 4.5 skips the correction for the low PCV.
Question 3 · Medium
Coarse basophilic stippling of red cells in a battery-factory worker with abdominal colic is due to aggregates of:
1. ADenatured haemoglobin, from oxidant injury
2. BIron granules, from blocked haem synthesis
3. CRibosomes, from impaired RNA breakdown
4. DNuclear DNA, from defective nuclear expulsion
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Answer: C · Ribosomes, from impaired RNA breakdown
Lead inhibits pyrimidine 5'-nucleotidase, the enzyme that degrades ribosomal RNA in maturing red cells. The undegraded ribosomes clump as the film dries and stain as many blue-black dots scattered evenly through the cell on a Romanowsky film. Lead also inhibits ALA dehydratase and ferrochelatase, which explains the anaemia. Iron-containing Pappenheimer bodies are fewer, clustered near the cell edge, and are confirmed with Perls' stain.
- A: Denatured haemoglobin forms Heinz bodies, seen only with supravital stains.
- B: Iron granules (Pappenheimer bodies) are few and peripheral, and stain with Perls' stain.
- D: DNA remnants form Howell-Jolly bodies, usually a single round dot.
Question 4 · Easy
Which cells produce most of the body's erythropoietin?
1. AJuxtaglomerular cells of the kidney
2. BStromal macrophages of the marrow
3. CPeritubular interstitial cells of the kidney
4. DHepatocytes around the central veins
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Answer: C · Peritubular interstitial cells of the kidney
About 90% of erythropoietin comes from peritubular interstitial cells in the renal cortex, which sense tissue oxygen through hypoxia-inducible factor. Hypoxia raises EPO output, which keeps CFU-E and early normoblasts alive and maturing. The liver makes a small share in adults but is the main source in the fetus. This is why chronic kidney disease causes a normocytic anaemia with a low reticulocyte count.
- A: Juxtaglomerular cells secrete renin, not erythropoietin.
- B: Marrow macrophages support erythroblastic islands but do not make EPO.
- D: The liver makes only about 10% of adult EPO, though it is the main fetal source.
Question 5 · Easy
Thrombopoietin, the main regulator of megakaryocyte growth and platelet production, is made chiefly in the:
1. AMarrow stromal cells
2. BLiver
3. CKidney
4. DMegakaryocytes
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Answer: B · Liver
Thrombopoietin is produced mainly by hepatocytes at a fairly constant rate, with small contributions from the kidney and marrow stroma. It binds the MPL receptor on megakaryocytes and platelets, so circulating platelets remove it: when the count falls, more free thrombopoietin reaches the marrow and platelet production rises. This explains why severe liver disease can contribute to thrombocytopenia. The kidney, by contrast, is the main source of erythropoietin.
- A: Marrow stroma makes a small share of thrombopoietin, not most of it.
- C: The kidney is the main source of erythropoietin; it makes only a little thrombopoietin.
- D: Megakaryocytes respond to thrombopoietin and help clear it; they do not make it.
Question 6 · Hard
Blood is diluted 1 in 20 in Turk's fluid, and 160 cells are counted in the four large corner squares of an improved Neubauer chamber. The film shows 25 nucleated red cells per 100 leucocytes. The corrected total leucocyte count is:
1. A10,000/µL
2. B8,000/µL
3. C6,000/µL
4. D6,400/µL
Answer and explanation in LearnFree account
Question 7 · Hard
A healthy 40-year-old man has a pre-operative platelet count of 38,000/µL on the analyser, with no bruising or bleeding. His EDTA film shows platelet clumps at the feathered edge and platelets ringed around neutrophils. What should the laboratory do next?
1. AReport severe thrombocytopenia urgently
2. BRequest a bone marrow aspiration
3. CRecount on the same EDTA sample
4. DRecollect in sodium citrate and recount
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Question 8 · Easy
Ring sideroblasts in a bone marrow aspirate are demonstrated with which stain?
1. AReticulin silver stain
2. BPeriodic acid-Schiff
3. CPerls' Prussian blue
4. DSudan black B
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Question 9 · Medium
A bone marrow aspirate has a myeloid to erythroid ratio of 1:2, and the blood reticulocyte count is 9%. What does this most likely show?
1. AGranulocytic hyperplasia of CML
2. BNormal adult marrow activity
3. CHypoplasia as in aplastic anaemia
4. DErythroid hyperplasia from haemolysis
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Question 10 · Medium
In a Romanowsky-stained film, the purple colour of neutrophil nuclear chromatin is produced by:
1. AMethylene blue binding alone to DNA
2. BOxidised haematoxylin with a metal mordant
3. CAzure B combined with eosin Y on DNA
4. DEosin Y binding to basic nuclear proteins
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Question 11 · Hard
A 68-year-old man with prostate cancer and back pain has Hb 9.2 g/dL, WBC 11,000/µL and platelets 1.1 lakh/µL. His film shows nucleated red cells, myelocytes, metamyelocytes and teardrop cells. Serum alkaline phosphatase is high. The most likely cause of the blood picture is:
1. ABone marrow infiltration by metastatic tumour
2. BChronic myeloid leukaemia
3. CIron deficiency from urinary blood loss
4. DAnaemia of chronic disease
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Question 12 · Easy
Reticulocytes are counted on a film stained with:
1. ANew methylene blue
2. BPerls Prussian blue
3. CSudan black B
4. DLeishman stain
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Question 13 · Easy
In the human embryo, the first blood cells are formed in the:
1. AFetal liver
2. BBone marrow
3. CFetal spleen
4. DYolk sac
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Question 14 · Hard
A 58-year-old man has Hb 19.5 g/dL and PCV 58%, with normal WBC and platelet counts and no splenomegaly. JAK2 V617F is negative, serum erythropoietin is high, and a CT scan shows a renal mass. The most likely diagnosis is:
1. ARelative polycythaemia from dehydration
2. BPolycythaemia vera
3. CChronic myeloid leukaemia
4. DSecondary polycythaemia from tumour erythropoietin
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Question 15 · Hard
An anaemic woman has a red cell count of 2.5 million/µL and a reticulocyte count of 4%. What is her absolute reticulocyte count?
1. A1,000,000/µL
2. B62,500/µL
3. C100,000/µL
4. D10,000/µL
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Question 16 · Hard
Blood is diluted 1 in 200 for a manual red cell count. 480 cells are counted in the 5 small squares (each 0.2 mm x 0.2 mm) of the central square of a Neubauer chamber. The red cell count is:
1. A2.4 million/µL
2. B0.48 million/µL
3. C4.8 million/µL
4. D48 million/µL
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Question 17 · Medium
Numerous schistocytes (fragmented red cells) on a blood film most strongly suggest:
1. AMegaloblastic anaemia
2. BHereditary spherocytosis
3. CIron deficiency anaemia
4. DMicroangiopathic haemolytic anaemia
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Question 18 · Medium
Hypersegmented neutrophils, with six or more nuclear lobes, are an early sign of:
1. AIron deficiency anaemia
2. BMegaloblastic anaemia
3. CAcute bacterial infection
4. DChronic myeloid leukaemia
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Question 19 · Medium
In normal erythropoiesis, the last stage that is still able to divide is the:
1. APolychromatic normoblast
2. BOrthochromatic normoblast
3. CBasophilic normoblast
4. DReticulocyte
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Question 20 · Hard
A trainee's wedge films are repeatedly too thick and short, with no thin feathered edge. The drop size is correct. Which change will most likely give a good film?
1. ADilute the blood with saline before spreading
2. BRaise the spreader angle to about 60 degrees
3. CLower the spreader angle to about 30 degrees
4. DUse a larger drop of blood on the slide
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Question 21 · Medium
A Leishman-stained film shows bright red red cells, pale blue nuclei and poorly seen neutrophil granules. The most likely cause is:
1. AStaining for too long
2. BBuffer that is too acidic
3. CA film that is too thick
4. DBuffer that is too alkaline
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Question 22 · Hard
An analyser gives Hb 11.8 g/dL, RBC 1.9 million/µL, MCV 128 fL and MCHC 44 g/dL on an elderly woman's sample. The film shows red cell clumps. What should be done before reporting?
1. ACollect a new sample in sodium citrate
2. BReport the results with a macrocytosis comment
3. CWarm the sample to 37°C and rerun it
4. DReplace the plasma with saline and rerun
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Question 23 · Medium
A patient's MCV was 88 fL last week. Today's EDTA sample, kept on the bench overnight before testing, gives MCV 96 fL and a lower MCHC, while Hb and the red cell count are unchanged. The most likely explanation is:
1. AToo much EDTA for the blood volume
2. BA cold agglutinin in the sample
3. CNew onset of B12 deficiency
4. DRed cell swelling during storage
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Question 24 · Medium
Target cells (codocytes) form because the red cell has:
1. APolymerised haemoglobin inside it
2. BDenatured haemoglobin on its membrane
3. CLost membrane but kept its volume
4. DExcess membrane for its volume
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Question 25 · Easy
In the Leishman staining method, the blood film is fixed by:
1. AFormalin vapour applied for one minute
2. BThe buffered water added in the second step
3. CThe methanol in which the stain is dissolved
4. DGentle heating over a flame before staining
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Haematopoiesis, cell counts and blood films

A spray-dried K2EDTA tube meant for 3 mL of blood receives only 1 mL. How are the spun PCV and the calculated MCHC affected?

A 24-year-old woman with jaundice and splenomegaly has a reticulocyte count of 9% and a PCV of 30%. Taking a normal PCV of 45% and a maturation time of 2 days at this PCV, what is her reticulocyte production index?

Coarse basophilic stippling of red cells in a battery-factory worker with abdominal colic is due to aggregates of:

Which cells produce most of the body's erythropoietin?

Thrombopoietin, the main regulator of megakaryocyte growth and platelet production, is made chiefly in the:

Blood is diluted 1 in 20 in Turk's fluid, and 160 cells are counted in the four large corner squares of an improved Neubauer chamber. The film shows 25 nucleated red cells per 100 leucocytes. The corrected total leucocyte count is:

A healthy 40-year-old man has a pre-operative platelet count of 38,000/µL on the analyser, with no bruising or bleeding. His EDTA film shows platelet clumps at the feathered edge and platelets ringed around neutrophils. What should the laboratory do next?

Ring sideroblasts in a bone marrow aspirate are demonstrated with which stain?

A bone marrow aspirate has a myeloid to erythroid ratio of 1:2, and the blood reticulocyte count is 9%. What does this most likely show?

In a Romanowsky-stained film, the purple colour of neutrophil nuclear chromatin is produced by:

A 68-year-old man with prostate cancer and back pain has Hb 9.2 g/dL, WBC 11,000/µL and platelets 1.1 lakh/µL. His film shows nucleated red cells, myelocytes, metamyelocytes and teardrop cells. Serum alkaline phosphatase is high. The most likely cause of the blood picture is:

Reticulocytes are counted on a film stained with:

In the human embryo, the first blood cells are formed in the:

A 58-year-old man has Hb 19.5 g/dL and PCV 58%, with normal WBC and platelet counts and no splenomegaly. JAK2 V617F is negative, serum erythropoietin is high, and a CT scan shows a renal mass. The most likely diagnosis is:

An anaemic woman has a red cell count of 2.5 million/µL and a reticulocyte count of 4%. What is her absolute reticulocyte count?

Blood is diluted 1 in 200 for a manual red cell count. 480 cells are counted in the 5 small squares (each 0.2 mm x 0.2 mm) of the central square of a Neubauer chamber. The red cell count is:

Numerous schistocytes (fragmented red cells) on a blood film most strongly suggest:

Hypersegmented neutrophils, with six or more nuclear lobes, are an early sign of:

In normal erythropoiesis, the last stage that is still able to divide is the:

A trainee's wedge films are repeatedly too thick and short, with no thin feathered edge. The drop size is correct. Which change will most likely give a good film?

A Leishman-stained film shows bright red red cells, pale blue nuclei and poorly seen neutrophil granules. The most likely cause is:

An analyser gives Hb 11.8 g/dL, RBC 1.9 million/µL, MCV 128 fL and MCHC 44 g/dL on an elderly woman's sample. The film shows red cell clumps. What should be done before reporting?

A patient's MCV was 88 fL last week. Today's EDTA sample, kept on the bench overnight before testing, gives MCV 96 fL and a lower MCHC, while Hb and the red cell count are unchanged. The most likely explanation is:

Target cells (codocytes) form because the red cell has:

In the Leishman staining method, the blood film is fixed by: