Q.1 Which of the following is the most commonly used anticoagulant for hematology tests?
EDTA
Heparin
Citrate
Oxalate
Explanation - EDTA chelates calcium and preserves cellular morphology, making it the preferred anticoagulant for complete blood counts and other hematology tests.
Correct answer is: EDTA
Q.2 What is the primary purpose of a Gram stain in microbiology?
To identify viruses
To differentiate bacterial species
To count white blood cells
To measure enzyme activity
Explanation - Gram staining differentiates bacteria into Gram-positive and Gram-negative based on cell wall properties, which helps guide initial antibiotic therapy.
Correct answer is: To differentiate bacterial species
Q.3 Which laboratory test is most specific for diagnosing myocardial infarction?
Creatine kinase (CK)
Troponin I
LDH
AST
Explanation - Troponin I is highly specific for myocardial injury and is the preferred marker for diagnosing acute myocardial infarction.
Correct answer is: Troponin I
Q.4 Which of the following tests is used to evaluate kidney function?
Serum bilirubin
Blood urea nitrogen (BUN)
Serum amylase
Prothrombin time
Explanation - BUN measures the amount of nitrogen in the blood in the form of urea and is a standard test to assess kidney function.
Correct answer is: Blood urea nitrogen (BUN)
Q.5 A 'left shift' in a complete blood count refers to an increase in:
Mature neutrophils
Immature neutrophils
Lymphocytes
Eosinophils
Explanation - A left shift indicates an increased number of immature neutrophils (band cells) in the blood, often due to infection or inflammation.
Correct answer is: Immature neutrophils
Q.6 Which of the following is considered a coagulation test?
ESR
PT
CRP
Serum iron
Explanation - Prothrombin time (PT) evaluates the extrinsic and common coagulation pathways and is commonly used to monitor anticoagulant therapy.
Correct answer is: PT
Q.7 Which microorganism is detected using acid-fast staining?
Staphylococcus aureus
Mycobacterium tuberculosis
Escherichia coli
Candida albicans
Explanation - Acid-fast staining is used to detect mycobacteria, such as M. tuberculosis, due to their waxy cell wall containing mycolic acid.
Correct answer is: Mycobacterium tuberculosis
Q.8 Which lab test is used to monitor long-term glucose control in diabetic patients?
Fasting glucose
HbA1c
Random glucose
Oral glucose tolerance test
Explanation - HbA1c reflects average blood glucose levels over the previous 2-3 months and is used to monitor chronic glycemic control.
Correct answer is: HbA1c
Q.9 Which of the following is a primary indicator of liver synthetic function?
Serum albumin
Serum bilirubin
AST
ALT
Explanation - Albumin is synthesized by the liver, and low serum levels indicate impaired liver synthetic function.
Correct answer is: Serum albumin
Q.10 Which of the following tests is used for detecting bacterial endotoxins in a laboratory setting?
ELISA
Limulus Amebocyte Lysate (LAL) test
PCR
Western blot
Explanation - The LAL test uses horseshoe crab blood cells to detect endotoxins, which are components of Gram-negative bacterial walls.
Correct answer is: Limulus Amebocyte Lysate (LAL) test
Q.11 What is the main purpose of a blood culture?
To measure hemoglobin
To identify pathogenic organisms in blood
To assess electrolyte balance
To evaluate liver function
Explanation - Blood cultures are performed to detect and identify microorganisms causing bloodstream infections.
Correct answer is: To identify pathogenic organisms in blood
Q.12 Which test is commonly used to evaluate thyroid function?
TSH
ALT
BUN
CRP
Explanation - Thyroid-stimulating hormone (TSH) is used to assess thyroid function; high TSH indicates hypothyroidism, low TSH indicates hyperthyroidism.
Correct answer is: TSH
Q.13 Which laboratory technique is most suitable for quantifying proteins in serum?
Nephelometry
PCR
Gram staining
Acid-fast staining
Explanation - Nephelometry measures light scattering by antigen-antibody complexes and is commonly used for quantitative protein assays.
Correct answer is: Nephelometry
Q.14 Which of the following is a marker for hemolysis in blood samples?
Elevated LDH
Elevated ALT
Low ESR
Low BUN
Explanation - Lactate dehydrogenase (LDH) levels rise when red blood cells are lysed, making it a useful marker of hemolysis.
Correct answer is: Elevated LDH
Q.15 Which type of urine specimen is preferred for routine urinalysis?
First morning specimen
Random specimen
24-hour urine
Catheterized specimen
Explanation - The first morning urine is concentrated and provides the most accurate representation of solutes and formed elements for urinalysis.
Correct answer is: First morning specimen
Q.16 Which hematologic test measures the average size of red blood cells?
MCV
MCHC
RDW
Hemoglobin
Explanation - Mean corpuscular volume (MCV) indicates the average volume of red blood cells and helps classify anemias as microcytic, normocytic, or macrocytic.
Correct answer is: MCV
Q.17 Which serological marker is used to detect recent hepatitis B infection?
HBsAg
Anti-HBc IgM
Anti-HBs
HBeAg
Explanation - The presence of IgM antibodies against hepatitis B core antigen indicates recent or acute hepatitis B infection.
Correct answer is: Anti-HBc IgM
Q.18 Which laboratory test is the gold standard for diagnosing diabetes mellitus?
Fasting plasma glucose
Oral glucose tolerance test
HbA1c
Random plasma glucose
Explanation - The OGTT is considered the gold standard because it directly assesses the body's ability to metabolize glucose over time.
Correct answer is: Oral glucose tolerance test
Q.19 Which of the following is used to measure coagulation time in platelets?
Bleeding time
PT
aPTT
INR
Explanation - Bleeding time assesses platelet function and the ability of small blood vessels to form a primary hemostatic plug.
Correct answer is: Bleeding time
Q.20 Which of the following specimens is preferred for microbiological examination of meningitis?
Blood
CSF
Urine
Sputum
Explanation - Cerebrospinal fluid (CSF) is obtained via lumbar puncture and analyzed for pathogens, white cells, and proteins in suspected meningitis.
Correct answer is: CSF
Q.21 Which laboratory test is elevated in hemolytic anemia?
Indirect bilirubin
Direct bilirubin
Serum albumin
Serum creatinine
Explanation - Hemolysis increases breakdown of red blood cells, leading to elevated unconjugated (indirect) bilirubin in the blood.
Correct answer is: Indirect bilirubin
Q.22 Which of the following is a normal platelet count range in adults?
150,000–450,000/µL
50,000–150,000/µL
450,000–700,000/µL
700,000–1,000,000/µL
Explanation - The normal adult platelet count ranges between 150,000 and 450,000 per microliter of blood.
Correct answer is: 150,000–450,000/µL
Q.23 Which of the following is used to determine the sedimentation rate of red blood cells?
ESR
CRP
PT
aPTT
Explanation - Erythrocyte sedimentation rate (ESR) measures the rate at which red blood cells settle in a tube and is a nonspecific marker of inflammation.
Correct answer is: ESR
Q.24 Which of the following is the first-line stain for cytology specimens?
Papanicolaou stain
Gram stain
Ziehl-Neelsen stain
Giemsa stain
Explanation - Papanicolaou stain is routinely used for cytology specimens like Pap smears, highlighting cellular details and nuclear morphology.
Correct answer is: Papanicolaou stain