Red cells washed in an open system must be transfused within 24 hours because:

Opening the bag risks bacterial contamination

Washing removes the anticoagulant

Washing activates the complement

The washed cells lose all 2,3-DPG

Four volunteers at a blood donation camp have normal weight, haemoglobin, pulse and temperature. Under NBTC 2017 guidelines, which one may donate today?

A man on metformin, sugar well controlled

A man given two units of blood 6 months ago

A man with a blood pressure of 160/100 mm Hg

A woman who delivered a baby 8 months ago

Under NBTC 2017 guidelines, which diabetic person may donate blood?

One controlled on oral drugs, no organ damage

One with diabetic kidney disease on tablets

One on insulin with frequent low sugars

One on insulin with good sugar control

Donor selection, components and transfusion reactions

50 Lab technician recruitment practice questions on Donor selection, components and transfusion reactions, part of Blood Banking and Immunohaematology. 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
Red cells washed in an open system must be transfused within 24 hours because:
1. AOpening the bag risks bacterial contamination
2. BWashing removes the anticoagulant
3. CWashing activates the complement
4. DThe washed cells lose all 2,3-DPG
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Answer: A · Opening the bag risks bacterial contamination
Washing red cells with saline removes plasma proteins, but an open (vented) system breaks the sterility of the bag. To limit the chance of bacterial growth, the unit expires 24 hours after washing at 2-6°C. Washed cells are given to patients with severe recurrent allergic reactions or with IgA deficiency and anti-IgA.
- B: The saline suspension does not clot, so anticoagulant loss is not the reason.
- C: Washing does not activate complement; it removes plasma.
- D: 2,3-DPG falls during storage, not suddenly with washing.
Question 2 · Easy
During storage of red cells at 2-6°C, which plasma constituent rises steadily?
1. AGlucose
2. B2,3-DPG
3. CpH
4. DPotassium
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Answer: D · Potassium
In the cold, the red cell sodium-potassium pump slows, so potassium leaks out of the cells and plasma potassium rises with each week of storage. At the same time 2,3-DPG, ATP, glucose and pH fall. These changes together are called the storage lesion. The potassium load matters in neonates and in rapid, large transfusions.
- A: Glucose falls as the cells use it for glycolysis.
- B: 2,3-DPG falls during storage, which raises the oxygen affinity of the stored cells.
- C: pH falls because lactic acid builds up from glycolysis.
Question 3 · Easy
Under NBTC guidelines, a person who has received a blood transfusion is deferred from donating for:
1. A3 months
2. BPermanently
3. C12 months
4. D6 months
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Answer: C · 12 months
A transfusion recipient may have acquired an infection in its window period from the donated unit, so NBTC guidelines defer such a person for 12 months. By then any HIV, hepatitis B or hepatitis C infection would be detectable on screening. The same 12-month deferral applies to other blood-borne exposures such as a tattoo or a needle-stick injury.
- A: Three months is too short to clear the window period of all screened infections.
- B: A past transfusion is a temporary, not a permanent, deferral.
- D: Six months is used for some surgical procedures, not for receiving blood.
Question 4 · Hard
Four volunteers at a blood donation camp have normal weight, haemoglobin, pulse and temperature. Under NBTC 2017 guidelines, which one may donate today?
1. AA man given two units of blood 6 months ago
2. BA man with a blood pressure of 160/100 mm Hg
3. CA woman who delivered a baby 8 months ago
4. DA man on metformin, sugar well controlled
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Answer: D · A man on metformin, sugar well controlled
A diabetic controlled on oral drugs and without end-organ damage is accepted. A woman is deferred for 12 months after delivery, so at 8 months she must wait. A person who has received blood is deferred for 12 months, so 6 months is too soon. A blood pressure of 160/100 mm Hg is above the accepted 140/90 mm Hg limit, so that donor is deferred and referred to a doctor.
- A: The 12-month deferral after a transfusion has not yet passed.
- B: Systolic and diastolic pressures are both above the accepted range.
- C: The 12-month deferral after delivery has not yet passed.
Question 5 · Easy
Under NBTC 2017 guidelines, which diabetic person may donate blood?
1. AOne with diabetic kidney disease on tablets
2. BOne on insulin with frequent low sugars
3. COne on insulin with good sugar control
4. DOne controlled on oral drugs, no organ damage
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Answer: D · One controlled on oral drugs, no organ damage
NBTC guidelines accept a diabetic whose sugar is controlled by diet or oral drugs and who has no damage to the heart, kidneys, eyes or nerves. A person who needs insulin is permanently deferred. A diabetic with end-organ damage is also deferred, whatever the treatment.
- A: End-organ damage such as nephropathy defers the donor.
- B: Insulin treatment alone defers the person, and hypoglycaemic episodes add risk.
- C: Any insulin-treated diabetic is permanently deferred, even with good control.
Question 6 · Medium
A donor's serum is reactive on RPR but non-reactive on TPHA. The most likely explanation is:
1. AEarly primary syphilis
2. BTreated old syphilis
3. CLate latent syphilis
4. DA biological false-positive RPR
Answer and explanation in LearnFree account
Question 7 · Easy
Under NBTC guidelines, the minimum interval between two plateletpheresis procedures on the same donor is:
1. A7 days
2. B28 days
3. C90 days
4. D48 hours
Answer and explanation in LearnFree account
Question 8 · Hard
Cryoprecipitate is the only factor VIII source in a district blood centre. A bleeding 60 kg man with factor VIII deficiency needs a 40% rise; 1 IU/kg gives about a 2% rise, and one bag holds 80 IU. How many bags are required?
1. A30 units
2. B8 units
3. C15 units
4. D20 units
Answer and explanation in LearnFree account
Question 9 · Medium
Fresh frozen plasma must be separated and frozen soon after collection mainly to preserve:
1. AFactors II, VII, IX and X
2. BImmunoglobulins
3. CFactors V and VIII
4. DFibrinogen and albumin
Answer and explanation in LearnFree account
Question 10 · Medium
When a platelet concentrate is held up to a light and gently pressed, a shimmering 'swirl' is seen. This shows that the platelets:
1. AContain many red cells
2. BAre contaminated with bacteria
3. CHave formed small aggregates
4. DKeep their normal disc shape
Answer and explanation in LearnFree account
Question 11 · Easy
Each unit of cryoprecipitate should contain at least how much factor VIII?
1. A1,000 IU
2. B80 IU
3. C250 IU
4. D8 IU
Answer and explanation in LearnFree account
Question 12 · Medium
In the buffy-coat method of platelet preparation, the first centrifugation of the whole blood unit is a:
1. AHard spin that pellets the platelets with red cells
2. BHard spin that leaves platelets in the buffy coat
3. CLight spin that gives platelet-rich plasma
4. DLight spin that separates only the plasma
Answer and explanation in LearnFree account
Question 13 · Hard
After a road accident, a man receives 12 units of red cells and 4 litres of crystalloid in 6 hours. He now oozes from wounds and drip sites. Results: platelets 42,000/µL, PT 24 s (control 13 s), fibrinogen 90 mg/dL, DAT negative. Which components does he need?
1. AFFP, platelets and cryoprecipitate
2. BMore red cells only
3. CWashed red cells and FFP
4. DAlbumin and crystalloid
Answer and explanation in LearnFree account
Question 14 · Medium
A blood donor is HBsAg negative but positive for anti-HBc, and HBV DNA is detected at a low level. This pattern is called:
1. AOccult hepatitis B infection
2. BResponse to hepatitis B vaccine
3. CPast infection with full immunity
4. DAcute hepatitis B in the window phase
Answer and explanation in LearnFree account
Question 15 · Medium
In an adult of average size, one random-donor platelet concentrate is expected to raise the platelet count by about:
1. A5,000-10,000/µL
2. B100,000/µL
3. C500-1,000/µL
4. D30,000-60,000/µL
Answer and explanation in LearnFree account
Question 16 · Easy
The recommended dose of gamma irradiation for a cellular blood component is:
1. A25 Gy to the centre of the bag
2. B50 Gy to the whole bag
3. C5 Gy to the centre of the bag
4. D2.5 Gy to the surface of the bag
Answer and explanation in LearnFree account
Question 17 · Medium
Platelet storage bags are made of a thinner, more gas-permeable plastic than red cell bags because platelets:
1. ANeed oxygen in and carbon dioxide out to keep their pH
2. BStick to ordinary PVC and form aggregates
3. CMust be protected from light during storage
4. DLeak potassium through ordinary PVC bags
Answer and explanation in LearnFree account
Question 18 · Hard
A patient's red cell unit runs through a line also carrying 5% dextrose. An hour later, the post-transfusion plasma is pink. Repeat ABO and Rh of patient and bag match, the DAT is negative and the antibody screen is negative. The most likely cause of the haemolysis is:
1. AAn ABO-incompatible transfusion
2. BA delayed haemolytic reaction
3. CA bacterially contaminated unit
4. DOsmotic lysis from the dextrose
Answer and explanation in LearnFree account
Question 19 · Easy
For a red cell preservative to be accepted, the mean recovery of transfused cells at 24 hours must be at least:
1. A50%
2. B95%
3. C25%
4. D75%
Answer and explanation in LearnFree account
Question 20 · Medium
During rapid transfusion of several cold units in an emergency, a patient develops a slow, irregular heart rhythm. The complication and its prevention are:
1. AAir embolism; use a pressure bag
2. BHypothermia; use an approved blood warmer
3. CHypocalcaemia; add calcium to the bag
4. DHyperkalaemia; give only fresh units
Answer and explanation in LearnFree account
Question 21 · Hard
A 15 kg child has a haemoglobin of 6 g/dL, and the target is 10 g/dL. Taking 4 mL/kg of packed red cells to raise haemoglobin by 1 g/dL, what volume should be ordered?
1. A60 mL
2. B600 mL
3. C240 mL
4. D360 mL
Answer and explanation in LearnFree account
Question 22 · Medium
A suspected transfusion reaction is reported to the blood bank. The first step in its laboratory investigation is to:
1. ARepeat the antibody screen on the post sample
2. BCulture the bag and the patient's blood
3. CDo an antibody identification panel
4. DCheck all labels, forms and records for a clerical error
Answer and explanation in LearnFree account
Question 23 · Easy
Requirements for licensed blood centres and blood components in India are laid down in:
1. ASchedule F Part XII B of the Drugs and Cosmetics Rules
2. BSchedule M of the Drugs and Cosmetics Rules
3. CSchedule Y of the Drugs and Cosmetics Rules
4. DSchedule I of the Bio-Medical Waste Rules
Answer and explanation in LearnFree account
Question 24 · Medium
Fresh frozen plasma is thawed in a 30-37°C water bath with the bag in a plastic overwrap. Why is it not thawed in hot water or a microwave oven?
1. AHeat lets bacteria grow faster
2. BHeat denatures clotting factors
3. CHeat makes cryoprecipitate re-form
4. DHeat activates complement in the plasma
Answer and explanation in LearnFree account
Question 25 · Hard
A leukaemia patient with a body surface area of 1.8 m² receives an apheresis platelet unit with 3.0 x 10^11 platelets. Counts: before 8,000/µL; one hour after 14,000/µL. Using CCI = (increment x BSA) / platelets given (x 10^11), what is the corrected count increment and its meaning?
1. A3,600; poor response (refractory)
2. B2,000; poor response (refractory)
3. C3,600; adequate response
4. D10,800; adequate response
Answer and explanation in LearnFree account

25 more Donor selection, components and transfusion reactions questions

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Donor selection, components and transfusion reactions

Red cells washed in an open system must be transfused within 24 hours because:

During storage of red cells at 2-6°C, which plasma constituent rises steadily?

Under NBTC guidelines, a person who has received a blood transfusion is deferred from donating for:

Four volunteers at a blood donation camp have normal weight, haemoglobin, pulse and temperature. Under NBTC 2017 guidelines, which one may donate today?

Under NBTC 2017 guidelines, which diabetic person may donate blood?

A donor's serum is reactive on RPR but non-reactive on TPHA. The most likely explanation is:

Under NBTC guidelines, the minimum interval between two plateletpheresis procedures on the same donor is:

Cryoprecipitate is the only factor VIII source in a district blood centre. A bleeding 60 kg man with factor VIII deficiency needs a 40% rise; 1 IU/kg gives about a 2% rise, and one bag holds 80 IU. How many bags are required?

Fresh frozen plasma must be separated and frozen soon after collection mainly to preserve:

When a platelet concentrate is held up to a light and gently pressed, a shimmering 'swirl' is seen. This shows that the platelets:

Each unit of cryoprecipitate should contain at least how much factor VIII?

In the buffy-coat method of platelet preparation, the first centrifugation of the whole blood unit is a:

After a road accident, a man receives 12 units of red cells and 4 litres of crystalloid in 6 hours. He now oozes from wounds and drip sites. Results: platelets 42,000/µL, PT 24 s (control 13 s), fibrinogen 90 mg/dL, DAT negative. Which components does he need?

A blood donor is HBsAg negative but positive for anti-HBc, and HBV DNA is detected at a low level. This pattern is called:

In an adult of average size, one random-donor platelet concentrate is expected to raise the platelet count by about:

The recommended dose of gamma irradiation for a cellular blood component is:

Platelet storage bags are made of a thinner, more gas-permeable plastic than red cell bags because platelets:

A patient's red cell unit runs through a line also carrying 5% dextrose. An hour later, the post-transfusion plasma is pink. Repeat ABO and Rh of patient and bag match, the DAT is negative and the antibody screen is negative. The most likely cause of the haemolysis is:

For a red cell preservative to be accepted, the mean recovery of transfused cells at 24 hours must be at least:

During rapid transfusion of several cold units in an emergency, a patient develops a slow, irregular heart rhythm. The complication and its prevention are:

A 15 kg child has a haemoglobin of 6 g/dL, and the target is 10 g/dL. Taking 4 mL/kg of packed red cells to raise haemoglobin by 1 g/dL, what volume should be ordered?

A suspected transfusion reaction is reported to the blood bank. The first step in its laboratory investigation is to:

Requirements for licensed blood centres and blood components in India are laid down in:

Fresh frozen plasma is thawed in a 30-37°C water bath with the bag in a plastic overwrap. Why is it not thawed in hot water or a microwave oven?

A leukaemia patient with a body surface area of 1.8 m² receives an apheresis platelet unit with 3.0 x 10^11 platelets. Counts: before 8,000/µL; one hour after 14,000/µL. Using CCI = (increment x BSA) / platelets given (x 10^11), what is the corrected count increment and its meaning?