Master Laboratory Operations for your laboratory certification exam with our comprehensive collection of 70 multiple-choice questions (MCQs). Focused exclusively on Laboratory Mathematics, these practice questions align with the latest syllabi of ASCP MLS, AMT MLT/MT, AIMS, CSMLS, IBMS, HAAD/DOH, DHA, and MOH exams. Each MCQ includes detailed explanations and references to reinforce key concepts. Sharpen your critical thinking, identify knowledge gaps, and build speed with exam-style questions—all for free. Ideal for targeted revision!
70 MCQs (132-201):
- An automated CK assay gives a reading above the linearity limit. A 1 mL serum sample is diluted with 9 mL of water, and the instrument reads 350 U/L. What is the correct report for the undiluted serum?
a) 2850 U/L
b) 3150 U/L
c) 3500 U/L
d) 3850 U/L - Standard solution concentration is commonly expressed in which unit?
a) g/L
b) mL/mL
c) mg/%
d) mol/L - A glucose determination has an absorbance of 0.30 for the standard and 0.20 for the unknown. The unknown’s value is:
a) 2/3 of the standard
b) 3/5 of the standard
c) Same as the standard
d) 1.5× the standard - What glassware is used to prepare a standard solution from a stock standard?
a) Graduated cylinder
b) Volumetric flask
c) Acid-washed beaker
d) Graduated flask - How many mL of red blood cells are needed to make 25 mL of a 4% suspension?
a) 0.25 mL
b) 0.5 mL
c) 1 mL
d) 2 mL - To prepare 100 mL of 5% sulfosalicylic acid from a 25% stock, the volume needed is:
a) 1.25 mL
b) 5 mL
c) 20 mL
d) 50 mL - To prepare 25 mL of 3% acetic acid, the volume of glacial acetic acid needed is:
a) 0.75 mL
b) 1.5 mL
c) 3.0 mL
d) 7.5 mL - How many grams of NaCl are needed to prepare 1 L of 0.9% normal saline?
a) 0.9 g
b) 1.8 g
c) 9.0 g
d) 18.0 g - To prepare 40 mL of a 3% solution, the volume of stock solution needed is:
a) 0.9 mL
b) 1.2 mL
c) 1.5 mL
d) 3.0 mL
- How much stock solution is needed to prepare 8 mL of a 75% solution?
a) 4.5 mL
b) 6.0 mL
c) 7.5 mL
d) 9.4 mL - A laboratory technician performs a recovery experiment with the following results:
– Mixture 1: 0.9 mL patient serum + 0.1 mL water → 89 mEq/L result
– Mixture 2: 0.9 mL same serum + 0.1 mL 800 mEq/L standard → 161 mEq/L result
What percentage of the added standard was recovered by the testing method?
a) 55%
b) 81%
c) 90%
d) 180% - A 0.25 mL sample diluted to 20 mL results in a dilution of:
a) 1:20
b) 1:40
c) 1:60
d) 1:80 - A serum glucose sample diluted 1:5 (Dilution A) and further 1:2 (Dilution B) must be multiplied by:
a) 5
b) 8
c) 10
d) 20 - A spinal fluid protein diluted 1:3 must be:
a) Multiplied by 3
b) Multiplied by 4
c) Divided by 3
d) Divided by 4 - How many mL of anti-D reagent are needed for 5 mL of a 1:25 dilution?
a) 0.1 mL
b) 0.2 mL
c) 0.25 mL
d) 0.5 mL - If 0.5 mL of a 1:300 dilution contains 1 antigenic unit, 2 units would be in 0.5 mL of:
a) 1:150
b) 1:450
c) 1:500
d) 1:600 - A 2% saline erythrocyte suspension contains how many mL of packed cells per 5 mL?
a) 0.1 mL
b) 0.2 mL
c) 0.5 mL
d) 1.0 mL - A 600 mg/dL glucose solution diluted 1:30 has a final concentration of:
a) 2 mg/dL
b) 20 mg/dL
c) 180 mg/dL
d) 1800 mg/dL - How many mL of 30% albumin are needed to make 6 mL of 10% albumin?
a) 1 mL
b) 2 mL
c) 3 mL
d) 4 mL - The formula for calculating dilutions is:
a) V1 + C1 = V2 + C2
b) V1 + C2 = V2 + C1
c) V1 × C1 = V2 × C2
d) V1 × V2 = C1 × C2 - A 0.1 mL serum + 5 mL reagent + 4.9 mL water results in a serum dilution of:
a) 1:5
b) 1:10
c) 1:50
d) 1:100 - A 1 mL serum + 4 mL water is a:
a) 1:3
b) 1:4
c) 1:5
d) 1:6 - The formula for % (w/v) solution is:
a) (grams solute/volume solvent) × 100
b) (grams solute × volume solvent) × 100
c) (volume solvent/grams solute) × 100
d) (grams solute × volume solvent)/100 - A solution with 20 g solute in 0.5 L water is:
a) 2%
b) 4%
c) 6%
d) 8% - How many grams of sulfosalicylic acid (MW=254) are needed for 1 L of 3% (w/v) solution?
a) 3 g
b) 30 g
c) 254 g
d) 300 g - How many mL of 3% solution can be made from 6 g solute?
a) 100 mL
b) 200 mL
c) 400 mL
d) 600 mL - A nanometer measures:
a) Wavelength of radiant energy
b) Specific gravity
c) Density
d) Light intensity - To make 1 L of 1.0 N NaOH from 1.025 N NaOH, the volume needed is:
a) 950.0 mL
b) 975.6 mL
c) 997.5 mL
d) 1025.0 mL - The sodium content in 100 g NaCl (Na=23, Cl=35.5) is:
a) 10 g
b) 20 g
c) 40 g
d) 60 g
- Given: Absorbance = 0.500, light path = 1.0 cm, concentration = 0.2 mol/L. The molar absorptivity is:
a) 0.4
b) 0.7
c) 1.6
d) 2.5 - The formula for gram equivalent weight (GEW) is:
a) MW × oxidation number
b) MW / oxidation number
c) MW + oxidation number
d) MW − oxidation number - 80 g NaOH (MW=40) is how many moles?
a) 1
b) 2
c) 3
d) 4 - A serum potassium (MW=39) value of 19.5 mg/100 mL equals:
a) 3.9 mEq/L
b) 4.2 mEq/L
c) 5.0 mEq/L
d) 8.9 mEq/L - The formula for moles of a chemical is:
a) grams / GMW
b) grams × GMW
c) GMW / grams
d) (grams × 100) / GMW - A 1 molal solution contains:
a) 1 mole solute per kg solvent
b) 1 mole solute in 1 L solution
c) 1 GEW solute in 1 L solution
d) 2 moles solute in 1 L solution - The formula for molarity is:
a) moles solute / L solution
b) moles solute × 100
c) 1 GEW solute × 10
d) 1 GEW solute / L solution - The molarity of 18.7 g KCl (MW=74.5) in 500 mL water is:
a) 0.1 M
b) 0.5 M
c) 1.0 M
d) 5.0 M - Adding 25 g NaOH (MW=40) to 0.5 L water, then diluting to 0.75 L, yields:
a) 0.25 M
b) 0.50 M
c) 0.75 M
d) 0.83 M - The normality of 280 g NaOH (MW=40) in 2000 mL solution is:
a) 3.5 N
b) 5.5 N
c) 7.0 N
d) 8.0 N - How many grams of H2SO4H2SO4 (MW=98) are in 750 mL of 3N H2SO4H2SO4?
a) 36 g
b) 72 g
c) 110 g
d) 146 g - How many mL of 0.25 N NaOH are needed to make 100 mL of 0.05 N NaOH?
a) 5 mL
b) 10 mL
c) 15 mL
d) 20 mL - A pH of 7.0 represents an H+H+ concentration of:
a) 70 mEq/L
b) 10 μmol/L
c) 7 nmol/L
d) 100 nmol/L - A solution with a precisely known concentration used to evaluate unknowns is a:
a) Standard
b) Normal
c) Control
d) Baseline - Hemoglobin controls have a mean of 15.2 g/dL and SD of 0.20. The ±2 SD range is:
a) 14.5–15.5 g/dL
b) 15.0–15.4 g/dL
c) 15.2–15.6 g/dL
d) 14.8–15.6 g/dL - The index of precision is the:
a) Median
b) Mean
c) Standard deviation
d) Coefficient of variation - Reproducibility is termed:
a) Sensitivity
b) Specificity
c) Accuracy
d) Precision - The ability to measure only the analyte of interest is:
a) Specificity
b) Sensitivity
c) Precision
d) Reproducibility - A correlation coefficient (r) of 0 indicates:
a) Complete correlation
b) No correlation
c) Positive correlation
d) Negative correlation - The formula for standard deviation is:
a) Square root of the mean
b) √[(sum of squared differences from mean)/(N−1)]
c) Square root of the variance
d) √(mean/sum of squared differences)
- With ±2 SD as the error limit, how many of 100 control values fall outside?
a) 1
b) 5
c) 10
d) 20 - For a mean of 100 and SD of 1.8 mg/dL, the 95% confidence interval is:
a) 94.6–105.4
b) 96.4–103.6
c) 97.3–102.7
d) 98.2–101.8 - Given mean WBC = 12,450/μL and SD = 153.2/μL, the CV is:
a) 0.01%
b) 1.2%
c) 2.5%
d) 8.1% - For sodium controls (140, 135, 138, 140, 142 mEq/L), the CV is:
a) 1.9%
b) 2.7%
c) 5.6%
d) 6.1% - The statistical term for the average value is the:
a) Mode
b) Median
c) Mean
d) Coefficient of variation - The most frequent value in a dataset is the:
a) Mode
b) Median
c) Mean
d) Standard deviation - The middle value in a dataset is the:
a) Mean
b) Median
c) Mode
d) Standard deviation - The formula for the arithmetic mean is:
a) √(sum of values)
b) Sum × number of values
c) Number of values / sum
d) Sum / number of values - For values (100, 120, 150, 140, 130), the mean is:
a) 100
b) 128
c) 130
d) 640 - The formula for CV is:
a) (SD × 100)/standard error
b) (Mean × 100)/SD
c) (SD/mean) × 100
d) (Variance × 100)/mean - For a cholesterol QC with mean = 137 mg/dL and SD = 3 mg/dL, the CV is:
a) 1.14%
b) 2.19%
c) 4.38%
d) 9.49% - Precision is validated by:
a) Replicate testing
b) Serial dilutions
c) Unknown specimens
d) Monitoring controls - Agreement with the true value is:
a) Reliability
b) Accuracy
c) Reproducibility
d) Precision - Diagnostic specificity is the percentage of:
a) True positives
b) True negatives
c) False negatives
d) False positives - The analytical measurement range (AMR) is verified to ensure:
a) Direct measurement without dilution
b) Reporting after pretreatment
c) Reporting up to 1:100 dilution
d) Reference lab verification - Predictive value of a positive test is:
a) (True positives + True negatives)/True positives × 100
b) True positives/(True positives + False positives) × 100
c) (True positives + True negatives)/True negatives × 100
d) True negatives/(True negatives + False positives) × 100 - Reliability of a test to detect disease is its:
a) Accuracy
b) Sensitivity
c) Precision
d) Specificity - Which parameter varies with disease prevalence?
a) Precision
b) Sensitivity
c) Accuracy
d) Specificity - A tight cluster of results on a target illustrates:
a) Accuracy
b) Precision
c) Sensitivity
d) Specificity - Limit of detection (LoD) is best described as:
a) Consensus value
b) Threshold reporting
c) Lowest detectable concentration
d) Blank sample probability - Limit of quantitation (LoQ) is the:
a) Lowest concentration measurable with accuracy
b) Lowest linear relationship
c) Closeness of replicate measurements
d) Blank sample result
Answer Key
Answer Key:
- c) 3500 U/L
- d) mol/L
- a) 2/3 of the standard
- b) Volumetric flask
- c) 1 mL
- c) 20 mL
- a) 0.75 mL
- c) 9.0 g
- b) 1.2 mL
- b) 6.0 mL
- c) 90%
- d) 1:80
- c) 10
- a) Multiplied by 3
- b) 0.2 mL
- a) 1:150
- a) 0.1 mL
- b) 20 mg/dL
- b) 2 mL
- c) V1 × C1 = V2 × C2
- d) 1:100
- c) 1:5
- a) (grams solute/volume solvent) × 100
- b) 4%
- b) 30 g
- b) 200 mL
- a) Wavelength of radiant energy
- b) 975.6 mL
- c) 40 g
- d) 2.5
- b) MW / oxidation number
- b) 2
- c) 5.0 mEq/L
- a) grams / GMW
- a) 1 mole solute per kg solvent
- a) moles solute / L solution
- b) 0.5 M
- d) 0.83 M
- a) 3.5 N
- c) 110 g
- d) 20 mL
- d) 100 nmol/L
- a) Standard
- d) 14.8–15.6 g/dL
- c) Standard deviation
- d) Precision
- a) Specificity
- b) No correlation
- b) √[(sum of squared differences from mean)/(N−1)]
- b) 5
- b) 96.4–103.6
- b) 1.2%
- a) 1.9%
- c) Mean
- a) Mode
- b) Median
- d) Sum / number of values
- b) 128
- c) (SD/mean) × 100
- b) 2.19%
- a) Replicate testing
- b) Accuracy
- b) True negatives
- a) Direct measurement without dilution
- b) True positives/(True positives + False positives) × 100
- b) Sensitivity
- c) Accuracy
- b) Precision
- c) Lowest detectable concentration
- a) Lowest concentration measurable with accuracy
Top 8 Medical Laboratory Scientist (MLS) Exams:
Top 8 Medical Laboratory Scientist (MLS) Exams that are recognized globally and can help professionals validate their credentials and enhance their career opportunities:
1. ASCP – American Society for Clinical Pathology (USA)
- Exam Name: MLS(ASCP)
- Eligibility: Bachelor’s degree with clinical laboratory experience.
- Global Recognition: High
- Purpose: Certifies Medical Laboratory Scientists in the United States and internationally.
2. AMT – American Medical Technologists (USA)
- Exam Name: MLT(AMT) or MT(AMT)
- Eligibility: Academic and/or work experience in medical laboratory technology.
- Global Recognition: Moderate
- Purpose: Credentialing for medical technologists and technicians.
3. AIMS – Australian Institute of Medical and Clinical Scientists
- Exam Name: AIMS Certification Exam
- Eligibility: Assessment of qualifications and work experience.
- Recognition: Required for practice in Australia.
- Purpose: Certification and registration in Australia.
4. CSMLS – Canadian Society for Medical Laboratory Science
- Exam Name: CSMLS General or Subject-specific Exams
- Eligibility: Graduation from a CSMLS-accredited program or equivalent.
- Recognition: Canada
- Purpose: Entry-to-practice certification in Canada.
5. IBMS – Institute of Biomedical Science (UK)
- Exam Name: Registration and Specialist Portfolio Assessment
- Eligibility: Accredited degree and lab experience.
- Recognition: UK and some Commonwealth countries.
- Purpose: Biomedical Scientist registration with the HCPC (UK).
6. HAAD / DOH – Department of Health, Abu Dhabi (UAE)
- Exam Name: DOH/HAAD License Exam
- Eligibility: Degree in medical laboratory science and experience.
- Recognition: UAE (Abu Dhabi)
- Purpose: Licensure for medical laboratory practice in Abu Dhabi.
7. DHA – Dubai Health Authority (UAE)
- Exam Name: DHA License Exam for Medical Laboratory Technologists
- Eligibility: Relevant degree and experience.
- Recognition: Dubai, UAE
- Purpose: Professional license for clinical laboratory practice in Dubai.
8. MOH – Ministry of Health (Gulf Countries like UAE, Saudi Arabia, Kuwait)
- Exam Name: MOH License Exam
- Eligibility: BSc/Diploma in Medical Laboratory + experience.
- Recognition: Varies by country.
- Purpose: Required for practicing in public and private sector labs.
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