50 free Lab Week trivia questions with answers — science & nature quiz, new questions added Aug 2026.
These lab week trivia questions were written for Medical Laboratory Professionals Week, the last full week of April, when hospital and clinic labs celebrate the scientists, technologists and phlebotomists behind roughly 70 percent of clinical decisions. The quiz covers every bench: blood banking (Landsteiner, ABO and Rh, universal donors), hematology (the CBC, hematocrit, Wright's stain, the Coulter counter, sed rate), microbiology (Gram stain, agar, Petri dishes, blood cultures, MRSA), chemistry and immunology (HbA1c, troponin, ELISA, PCR) and the history of the lab from Leeuwenhoek and Hooke to HeLa cells and CLIA. It opens with a few questions about Lab Week itself. About a third of the questions are easy for anyone who has worked in or around a lab, a third are medium, and the rest will separate the specialists from the generalists. Use it for a break-room quiz, a Lab Week competition between departments, or a student review. Every answer has been checked against an encyclopaedic or professional-society source and each question links to the page that confirms it.
30 of 50 questions with answers and explanations. Play the quiz
Q 01When is Medical Laboratory Professionals Week held each year?
Last full seven days of April
It is coordinated by a committee of lab organisations led by ASCLS, and in 2026 fell on April 19–25.
Q 02In which year did Lab Week begin, under the name National Medical Laboratory Week?
1975
'Professionals' was added in 2005 and 'National' was dropped in 2012, giving the current name.
Q 03Roughly what share of clinical decisions in acute-care hospitals is based on laboratory testing?
70%
That statistic is the one Lab Week posters lean on hardest, and it comes from the definition of what a medical laboratory does.
Q 04Which Chicago-based body, founded in 1922, certifies most US laboratory professionals?
ASCP
ASCP represents about 130,000 pathologists and lab professionals and publishes LabMedicine.
Q 05Who identified the main human blood groups in 1901 and won the 1930 Nobel Prize for it?
Karl Landsteiner
He went on to co-discover the Rh factor in 1937 and the polio virus in 1909.
Q 06Which blood type is often called the 'universal donor' for red cell transfusions?
O−
O Rh D-negative red cells can go to almost anyone; AB positive individuals are the universal recipients, and guidelines now try to reserve O-negative units for true emergencies.
Q 07How many blood group systems did the International Society of Blood Transfusion recognise by June 2025?
48
ABO and Rh matter most, but the list runs from Kell and Duffy to systems most people have never heard of.
Q 08In the Rh system, which single antigen determines whether someone is 'Rh positive' or 'Rh negative'?
D
There are more than 50 Rh antigens, and there is no such thing as a 'd' antigen.
Q 09People with the rare 'hh' blood group, first found in Mumbai, can only receive transfusions from whom?
Fellow hh individuals
They make antibodies against A, B and O alike, which is how a type O child can be born to an AB parent.
Q 10What does CBC stand for?
Complete blood count
It reports white cells, red cells, platelets, hemoglobin and hematocrit, plus red-cell indices and often a differential.
Q 11Hematocrit measures what?
The volume percentage of red cells in blood
Normal is roughly 41–50% for men and 36–44% for women; low values suggest anaemia.
Q 12Wright's stain, used on blood smears, mixes methylene blue with which red dye?
Eosin
James Homer Wright devised it in 1902 as a modification of the Romanowsky stain.
Q 13Platelets are fragments of cytoplasm shed by which large bone-marrow cells?
Megakaryocytes
They have no nucleus; in birds and amphibians the equivalent thrombocytes circulate as whole cells.
Q 21In a Gram stain, what is the primary stain that gram-positive bacteria retain?
Crystal violet
Lugol's iodine is added afterwards to lock the dye into the thick peptidoglycan layer.
Q 22Who suggested replacing gelatin with agar in culture media after gelatin kept melting?
Fanny Hesse
Her husband Walther was working in Robert Koch's lab in 1881; agar changed microbiology for good.
Q 23In what year did Petri make the final modifications to the culture dish that bears his name?
1887
His boss Robert Koch had developed a precursor in his private lab in 1881.
Q 14The erythrocyte sedimentation rate is measured after how long in a Westergren tube?
One hour
Westergren's original normals were 3 mm/h for men and 7 mm/h for women, with no allowance for age.
Q 15The automated cell counter that revolutionised the CBC works on a principle discovered by whom in the 1940s?
Wallace Coulter
Each cell passing through a tiny aperture changes the electrical resistance; the patent wasn't granted until 1953.
Q 16Prothrombin time (PT/INR) is used to monitor patients taking which anticoagulant?
Warfarin
It evaluates the extrinsic and common clotting pathways; aPTT covers the intrinsic pathway.
Q 17Serum differs from plasma in lacking what?
Clotting factors
Plasma is about 55% of blood volume and up to 95% water; the study of serum is serology.
Q 18Who invented the Vacutainer evacuated blood-collection tube in 1949?
Joseph Kleiner
The stopper colour signals the additive inside: EDTA, sodium citrate, heparin or a separator gel.
Q 19What is a person who draws blood for a living called?
A phlebotomist
Phlebectomy, by contrast, is the removal of a vein; a therapeutic phlebotomy takes about a unit, 450–500 ml.
Q 20Which Danish bacteriologist devised the 1884 stain that sorts bacteria into 'positive' and 'negative'?
Hans Christian Gram
Gram-positive walls keep the crystal violet; gram-negatives lose it to ethanol and take up the pink safranin.
Q 24Whose 1876 discovery of Bacillus anthracis is considered the birth of modern bacteriology?
Robert Koch
He later identified the causes of tuberculosis and cholera too, and won the 1905 Nobel Prize for the TB work.
Q 25A standard set of blood cultures consists of two bottles for which two kinds of organism?
Aerobic and anaerobic
Two sets from two sites are often drawn to tell a real bacteraemia from a skin contaminant.
Q 26MRSA is a strain of Staphylococcus aureus resistant to which family of antibiotics?
Beta-lactams
That covers methicillin, oxacillin and the cephalosporins; susceptible strains are called MSSA.
Q 27Which self-taught Dutch draper is known as the 'Father of Microbiology' for his 1670s microscope work?
Antonie van Leeuwenhoek
He ground his own lenses in Delft and was the first to describe microbial life.
Q 28Who coined the word 'cell' in his 1665 book Micrographia?
Robert Hooke
He was looking at cork through a compound microscope of his own design.
Q 29Who invented the polymerase chain reaction in 1983, at Cetus Corporation?
Kary Mullis
He shared the 1993 Nobel Prize in Chemistry with Michael Smith and was famously eccentric outside the lab.
Q 30Taq polymerase, which made PCR practical, came from a bacterium found where?
Hot springs
Thermus aquaticus can take the near-boiling denaturation step; before it, fresh polymerase had to be added every cycle.