Cell line studies MCQs With Answer

Cell line studies MCQs With Answer

This collection of multiple-choice questions is tailored for M.Pharm students preparing for examinations and practical assessments in Biological Evaluation of Drug Therapy. The quiz focuses on key topics in cell line studies including cell line types, authentication, contamination control, growth parameters, cytotoxicity and viability assays, transfection methods, cryopreservation, cell banking, and Good Cell Culture Practice (GCCP). Questions are designed to test both conceptual understanding and practical laboratory decision-making, with emphasis on assay selection, data interpretation, and troubleshooting common problems in cell culture. Use these MCQs to reinforce theoretical knowledge and improve readiness for research and industry roles involving in vitro cell-based studies.

Q1. What distinguishes a primary cell line from an immortalized (continuous) cell line?

• Primary cell lines are derived directly from tissues and have a limited lifespan in culture; immortalized cell lines can proliferate indefinitely
• Primary cell lines always grow in suspension while immortalized lines are always adherent
• Primary cell lines are genetically modified, immortalized lines are always unmodified
• Primary cell lines tolerate serum-free media better than immortalized cell lines

Correct Answer: Primary cell lines are derived directly from tissues and have a limited lifespan in culture; immortalized cell lines can proliferate indefinitely

Q2. Which method is most commonly used to immortalize mammalian cells for continuous culture?

• Spontaneous senescence induction
• Expression of viral oncogenes such as SV40 large T antigen or hTERT overexpression
• Repeated serum starvation cycles
• Exposure to low oxygen tension (hypoxia)

Correct Answer: Expression of viral oncogenes such as SV40 large T antigen or hTERT overexpression

Q3. Short tandem repeat (STR) profiling of cell lines is primarily used to:

• Measure cell doubling time
• Authenticate cell line identity and detect cross-contamination
• Quantify mycoplasma contamination levels
• Determine optimal serum concentration

Correct Answer: Authenticate cell line identity and detect cross-contamination

Q4. Which assay is most specific for routine mycoplasma detection in cell cultures?

• Gram staining
• PCR-based mycoplasma detection
• MTT cell viability assay
• Trypan blue exclusion

Correct Answer: PCR-based mycoplasma detection

Q5. If a cell population increases from 1 x 10^5 to 8 x 10^5 cells in 24 hours, what is the doubling time?

• Approx. 12 hours
• Approx. 8 hours
• Approx. 24 hours
• Approx. 6 hours

Correct Answer: Approx. 8 hours

Q6. In cell culture, what does “confluence” refer to?

• The percentage of cells that are viable in a culture
• The proportion of culture surface covered by adherent cells
• The level of contamination by microorganisms
• The amount of serum in the medium

Correct Answer: The proportion of culture surface covered by adherent cells

Q7. What is the recommended method for cryopreserving mammalian cell lines to maximize viability?

• Rapid plunge freezing in liquid nitrogen without cryoprotectant
• Controlled-rate freezing (~1°C/min) with 5–10% DMSO as cryoprotectant
• Air-drying cells at room temperature
• Freezing cells directly at −20°C

Correct Answer: Controlled-rate freezing (~1°C/min) with 5–10% DMSO as cryoprotectant

Q8. Why is monitoring passage number important in cell line experiments?

• Passage number has no effect on experimental reproducibility
• High passage numbers may lead to genetic drift, phenotypic changes and altered drug responses
• Lower passage cells are always contaminated
• Passage number only affects suspension cultures

Correct Answer: High passage numbers may lead to genetic drift, phenotypic changes and altered drug responses

Q9. Which observation most strongly suggests cross-contamination of a cell line with HeLa cells?

• Slight decrease in growth rate
• Sudden change to epithelial-like morphology, high proliferative capacity and STR profile matching HeLa
• Increased sensitivity to serum withdrawal
• Reduced adherence to plastic

Correct Answer: Sudden change to epithelial-like morphology, high proliferative capacity and STR profile matching HeLa

Q10. What is the main difference between transient and stable transfection?

• Transient transfection integrates the transgene into the host genome permanently
• Stable transfection results in long-term expression due to genomic integration or selection, while transient transfection yields short-term expression without integration
• Transient transfection requires antibiotic selection markers for maintenance
• Stable transfection cannot be used for protein expression studies

Correct Answer: Stable transfection results in long-term expression due to genomic integration or selection, while transient transfection yields short-term expression without integration

Q11. In viral transduction experiments, what does MOI (multiplicity of infection) represent?

• The volume of virus added per well
• The ratio of infectious viral particles to target cells
• The number of different viral strains used
• The time required for infection to occur

Correct Answer: The ratio of infectious viral particles to target cells

Q12. Which advantage do 3D spheroid cultures have over traditional 2D monolayers for drug testing?

• They eliminate the need for cell authentication
• They better recapitulate tumor microenvironment gradients such as nutrient, oxygen and drug penetration profiles
• They always grow faster than 2D cultures
• They are less expensive and require no specialized equipment

Correct Answer: They better recapitulate tumor microenvironment gradients such as nutrient, oxygen and drug penetration profiles

Q13. Which statement correctly contrasts MTT and resazurin (Alamar Blue) assays?

• MTT is non-colorimetric while resazurin produces a formazan precipitate
• MTT produces an insoluble formazan requiring solubilization; resazurin is reduced to a soluble fluorescent product allowing non-destructive, kinetic measurements
• Both assays are identical in chemistry and detection method
• Resazurin is toxic to all cell types while MTT is universally non-toxic

Correct Answer: MTT produces an insoluble formazan requiring solubilization; resazurin is reduced to a soluble fluorescent product allowing non-destructive, kinetic measurements

Q14. Which marker is most commonly used to detect early apoptosis in cultured cells?

• Propidium iodide uptake
• Annexin V binding to externalized phosphatidylserine
• MG-132 accumulation
• Calcein AM efflux

Correct Answer: Annexin V binding to externalized phosphatidylserine

Q15. High-content screening (HCS) platforms in cell line studies primarily combine which two elements?

• Bulk protein quantification and PCR
• Automated fluorescence microscopy and multiparametric image analysis for phenotypic profiling
• Only plate reader absorbance measurements
• Manual microscopy with single-endpoint readout

Correct Answer: Automated fluorescence microscopy and multiparametric image analysis for phenotypic profiling

Q16. One major benefit of using defined serum-free media for cell culture is:

• Serum-free media always increase proliferation rates
• Improved reproducibility and reduced variability due to elimination of undefined serum components
• Complete protection against contamination
• They allow immortalization of primary cells without genetic manipulation

Correct Answer: Improved reproducibility and reduced variability due to elimination of undefined serum components

Q17. How can mycoplasma contamination alter experimental outcomes in cell-based assays?

• Mycoplasma generally has no effect on cell metabolism or assay readouts
• It can modify cellular metabolism, gene expression, drug sensitivity and produce subtle changes that confound results
• It only changes the color of culture medium without affecting cells
• It causes immediate lysis of all cultured cells

Correct Answer: It can modify cellular metabolism, gene expression, drug sensitivity and produce subtle changes that confound results

Q18. In a cell banking system, what is the primary purpose of a Master Cell Bank (MCB)?

• To be used directly for routine assays and frequent thawing
• To serve as the original, well-characterized source from which Working Cell Banks are derived
• To contain cells adapted to high passage numbers for production
• To store contaminated cultures for decontamination studies

Correct Answer: To serve as the original, well-characterized source from which Working Cell Banks are derived

Q19. Which practice is a core element of Good Cell Culture Practice (GCCP)?

• Never record passage numbers or culture conditions
• Rigorous documentation, regular authentication, aseptic technique and defined SOPs for handling cell lines
• Maintaining a single medium for all cell types without optimization
• Sharing cell stocks freely without labeling

Correct Answer: Rigorous documentation, regular authentication, aseptic technique and defined SOPs for handling cell lines

Q20. Which assay is a standard method to assess anchorage-independent growth, a hallmark of cellular transformation?

• Soft agar colony formation assay
• Transwell migration assay
• LDH cytotoxicity assay
• Glucose uptake assay

Correct Answer: Soft agar colony formation assay

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