Primary cell cultures MCQs With Answer provide B. Pharm students a focused, exam-oriented review of primary cell culture principles, isolation methods, and laboratory best practices. This concise guide covers isolation techniques (enzymatic and explant), media selection, sterility, cryopreservation, viability assays, contamination control, and ethical sourcing of tissues. Targeted keywords such as primary cell culture, cell isolation, cell viability assays, culture media, and B. Pharm practicals are integrated to boost SEO and help students retain clinically relevant lab concepts. Clear, application-based questions reinforce troubleshooting and technique precision essential for pharmaceutical research and quality control. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What defines a primary cell culture?
- Immortalized cells adapted for long-term growth
- Cells freshly derived from tissues that have limited lifespan in vitro
- Cells grown on synthetic polymers only
- Cell lines genetically modified for stability
Correct Answer: Cells freshly derived from tissues that have limited lifespan in vitro
Q2. Which method is commonly used for enzymatic dissociation of tissues into primary cells?
- Trypsinization
- Sonication
- Autoclaving
- Freeze-thaw cycles
Correct Answer: Trypsinization
Q3. Which enzyme is preferred for gentle dissociation of liver cells (hepatocytes)?
- Collagenase
- RNase
- Lysozyme
- Pepsin
Correct Answer: Collagenase
Q4. What is the explant method?
- Using UV light to sterilize explants
- Placing small tissue pieces directly in culture to allow cell outgrowth
- Disrupting cells by vortexing explants
- Embedding cells in agarose for growth
Correct Answer: Placing small tissue pieces directly in culture to allow cell outgrowth
Q5. Which serum supplement is most commonly used in primary cell culture media?
- Fetal bovine serum (FBS)
- Human insulin only
- Egg yolk extract
- Plant-based serum
Correct Answer: Fetal bovine serum (FBS)
Q6. Why are primary cultures considered more physiologically relevant than immortalized cell lines?
- They proliferate indefinitely
- They maintain tissue-specific functions and phenotype closer to in vivo
- They require no sterile technique
- They are easier to transfect than cell lines
Correct Answer: They maintain tissue-specific functions and phenotype closer to in vivo
Q7. Which parameter is crucial to monitor for maintaining pH in CO2 incubators?
- CO2 concentration
- Humidity only
- Light intensity
- Oxygen level only
Correct Answer: CO2 concentration
Q8. Which assay measures cell membrane integrity to assess viability in primary cells?
- Trypan blue exclusion test
- Western blot
- ELISA for cytokines
- Gram staining
Correct Answer: Trypan blue exclusion test
Q9. What is the main purpose of using dimethyl sulfoxide (DMSO) in cryopreservation?
- To stain cells for microscopy
- To act as a cryoprotectant and prevent ice crystal formation
- To increase cell proliferation at room temperature
- To denature proteins during thawing
Correct Answer: To act as a cryoprotectant and prevent ice crystal formation
Q10. Which contamination is hardest to detect and can alter cellular metabolism without visible turbidity?
- Fungal contamination
- Bacterial contamination
- Mycoplasma contamination
- Cellular senescence
Correct Answer: Mycoplasma contamination
Q11. In primary culture, what does ‘passaging’ refer to?
- Discarding cell medium without replacement
- Transferring cells to fresh vessels to prevent overconfluency and maintain growth
- Fixing cells for staining
- Measuring DNA content only
Correct Answer: Transferring cells to fresh vessels to prevent overconfluency and maintain growth
Q12. Which growth factor is commonly used to support primary neuronal cultures?
- Insulin-like growth factor (IGF)
- Nerve growth factor (NGF)
- Vascular endothelial growth factor (VEGF)
- Epidermal growth factor (EGF) exclusively
Correct Answer: Nerve growth factor (NGF)
Q13. What is contact inhibition?
- Increased proliferation at high density
- Inhibition of cell division when cells form a continuous monolayer
- Cell death due to overexposure to serum
- Enhanced cell migration in culture
Correct Answer: Inhibition of cell division when cells form a continuous monolayer
Q14. Which microscope technique is most appropriate for observing live primary cell morphology?
- Scanning electron microscopy
- Phase-contrast microscopy
- Transmission electron microscopy
- Confocal microscopy with heavy fixation only
Correct Answer: Phase-contrast microscopy
Q15. Which buffer is commonly used to wash cells before trypsinization?
- Phosphate-buffered saline (PBS)
- Tris-HCl for PCR
- EDTA-free water
- Acetone
Correct Answer: Phosphate-buffered saline (PBS)
Q16. What is a typical seeding density consideration for establishing primary fibroblast cultures?
- Very low density to avoid any contact
- Appropriate density to allow attachment and proliferation without overconfluency
- Maximum possible density for immediate confluency
- Seeding density is irrelevant for fibroblasts
Correct Answer: Appropriate density to allow attachment and proliferation without overconfluency
Q17. Which medium component maintains osmolarity and acts as a nutrient in cell culture?
- Antibiotics
- Balanced salts and glucose found in basal media
- Phenol red exclusively
- Trypsin
Correct Answer: Balanced salts and glucose found in basal media
Q18. For primary epithelial cells, what surface coating often enhances attachment?
- Poly-L-lysine or collagen coatings
- Silicone oil layer
- Plain glass without coating
- Heavy metal ions
Correct Answer: Poly-L-lysine or collagen coatings
Q19. Which is a key ethical consideration when sourcing human primary cells for B. Pharm labs?
- Using any tissue without documentation
- Obtaining informed consent and ethical approval for tissue collection
- Only collecting tissue from minors without consent
- Purchasing tissue anonymously without records
Correct Answer: Obtaining informed consent and ethical approval for tissue collection
Q20. What is the main reason to include antibiotics in primary cell culture media?
- To accelerate growth of desired cells
- To reduce the risk of bacterial contamination during primary isolation
- To replace the need for sterile technique
- To stain bacteria for microscopy
Correct Answer: To reduce the risk of bacterial contamination during primary isolation
Q21. Which parameter is NOT typically critical for primary cell culture success?
- Temperature (37°C for mammalian cells)
- CO2 concentration
- Ambient room noise level
- Humidity
Correct Answer: Ambient room noise level
Q22. How is cell confluency usually estimated?
- By visually assessing the percentage of surface covered by cells under microscope
- By measuring DNA content only
- By counting only dead cells
- By color of the medium exclusively
Correct Answer: By visually assessing the percentage of surface covered by cells under microscope
Q23. Which technique is used to detect mycoplasma contamination?
- Trypan blue exclusion
- PCR-based assays or specific staining kits
- Gram staining
- Flow cytometry for surface markers only
Correct Answer: PCR-based assays or specific staining kits
Q24. What is the recommended thawing practice for cryopreserved primary cells?
- Slow thaw at room temperature for several hours
- Rapid thawing in a 37°C water bath followed by dilution and removal of DMSO
- Direct placement into a -20°C freezer
- Thawing under UV light
Correct Answer: Rapid thawing in a 37°C water bath followed by dilution and removal of DMSO
Q25. Which metric indicates proliferative potential during primary culture establishment?
- Cell doubling time
- pH of the medium only
- Color of the culture vessel
- Magnetic susceptibility
Correct Answer: Cell doubling time
Q26. In primary cultures, what role does extracellular matrix (ECM) play?
- Provides mechanical and biochemical cues for attachment, differentiation, and signaling
- Increases contamination
- Replaces the need for growth factors
- Acts as the main carbon source
Correct Answer: Provides mechanical and biochemical cues for attachment, differentiation, and signaling
Q27. Which centrifugation practice is appropriate when harvesting fragile primary cells?
- Use very high g-forces to speed up pelleting
- Use low to moderate g-forces and short durations to minimize damage
- Do not use centrifugation at all
- Freeze samples before centrifugation
Correct Answer: Use low to moderate g-forces and short durations to minimize damage
Q28. What does serum-free culture aim to achieve for certain primary cells?
- Reduce reproducibility by removing defined components
- Provide controlled conditions with defined supplements to study growth factor effects
- Increase unknown variables
- Prevent cell attachment permanently
Correct Answer: Provide controlled conditions with defined supplements to study growth factor effects
Q29. Which cell type in primary culture often requires a feeder layer for support?
- Fibroblasts exclusively
- Embryonic stem cells or some progenitor cells
- Red blood cells
- Mature erythrocytes
Correct Answer: Embryonic stem cells or some progenitor cells
Q30. Why is phenol red included in many culture media?
- As a pH indicator to monitor culture acidity
- To increase cell proliferation directly
- To prevent bacterial growth
- As a fluorescent dye for flow cytometry
Correct Answer: As a pH indicator to monitor culture acidity
Q31. Which primary cell isolation source is most commonly used for peripheral blood mononuclear cells (PBMCs)?
- Bone marrow biopsy
- Peripheral blood using density gradient centrifugation
- Skin explants
- Urine samples
Correct Answer: Peripheral blood using density gradient centrifugation
Q32. What is a growth curve in cell culture studies?
- A plot of medium color changes over time
- A graph showing phases of cell proliferation: lag, log, stationary, and decline
- Measurement of gas exchange only
- Counting only dead cells across time
Correct Answer: A graph showing phases of cell proliferation: lag, log, stationary, and decline
Q33. Which precaution reduces endotoxin introduction in primary cultures?
- Using non-sterile reagents
- Using endotoxin-free reagents, glassware, and aseptic technique
- Adding extra serum only
- Heating samples to 100°C frequently
Correct Answer: Using endotoxin-free reagents, glassware, and aseptic technique
Q34. When isolating primary cells from solid tissue, why is mechanical mincing performed before enzymatic digestion?
- To sterilize the tissue
- To increase surface area for more efficient enzymatic action
- To selectively remove fibroblasts only
- To cool the tissue rapidly
Correct Answer: To increase surface area for more efficient enzymatic action
Q35. What is the main advantage of early-passage primary cells in experiments?
- They are less costly than late-passage cells
- They retain more in vivo-like phenotype and genetic stability
- They grow exponentially forever
- They are always free of contamination
Correct Answer: They retain more in vivo-like phenotype and genetic stability
Q36. Which method is used to count cells in a suspension accurately?
- Hemocytometer counting under microscope
- Using a balance to weigh cells
- Color of medium only
- Counting after embedding in paraffin
Correct Answer: Hemocytometer counting under microscope
Q37. Which factor primarily determines the shelf-life of frozen primary cell stocks?
- Type of culture vessel used
- Proper cryopreservation protocol and storage in liquid nitrogen
- Color of cryovials
- Frequency of opening incubator doors
Correct Answer: Proper cryopreservation protocol and storage in liquid nitrogen
Q38. For primary neuronal cultures, why is gentleness during dissociation critical?
- Neurons are robust and need harsh treatment
- Neurons are fragile and excessive mechanical or enzymatic stress reduces viability and function
- Gentleness reduces contamination risk only
- It accelerates cell division
Correct Answer: Neurons are fragile and excessive mechanical or enzymatic stress reduces viability and function
Q39. What is the role of EDTA in cell dissociation buffers?
- To provide growth factors
- To chelate divalent cations and weaken cell-cell adhesion
- To stain nuclei
- To increase viscosity of medium
Correct Answer: To chelate divalent cations and weaken cell-cell adhesion
Q40. Which statement about primary cell transfection is true?
- Primary cells are generally easier to transfect than immortalized lines
- Primary cells often require optimized, gentle transfection methods due to lower transfection efficiency and sensitivity
- Transfection is unnecessary for primary cells
- Any transfection reagent works equally well for all primary cell types
Correct Answer: Primary cells often require optimized, gentle transfection methods due to lower transfection efficiency and sensitivity
Q41. What is the effect of prolonged exposure to trypsin during primary cell detachment?
- Enhanced attachment after passaging
- Potential damage to cell surface proteins and reduced viability
- Complete sterilization of culture
- Increase in cell size permanently
Correct Answer: Potential damage to cell surface proteins and reduced viability
Q42. Which contaminant often produces fuzzy colonies and grows slower than bacteria in culture?
- Yeast/fungal contamination
- Viruses only
- Mycoplasma only
- Plasmids
Correct Answer: Yeast/fungal contamination
Q43. For quality control, why is cell authentication important in primary culture studies?
- To ensure correct cell identity and prevent misinterpretation due to cross-contamination or mislabeling
- To increase contamination risk
- To reduce experimental reproducibility
- To ensure cells are immortal
Correct Answer: To ensure correct cell identity and prevent misinterpretation due to cross-contamination or mislabeling
Q44. Which condition favors fibroblast overgrowth in mixed primary cultures?
- Low serum and controlled conditions
- High serum and rapid adherence advantage of fibroblasts
- Using neuronal-specific medium only
- Feeder layers that inhibit fibroblasts
Correct Answer: High serum and rapid adherence advantage of fibroblasts
Q45. Which assay measures metabolic activity as an indicator of viable primary cells?
- MTT or resazurin (Alamar Blue) assay
- Gram staining
- Electron microscopy only
- pH strip test exclusively
Correct Answer: MTT or resazurin (Alamar Blue) assay
Q46. When establishing primary cultures, why is immediate processing of tissue samples recommended?
- To ensure sterility only
- To preserve cell viability and reduce ischemic damage that lowers yield and function
- To increase bacterial growth intentionally
- Processing time does not affect primary cultures
Correct Answer: To preserve cell viability and reduce ischemic damage that lowers yield and function
Q47. Which factor commonly causes acidic shift in culture medium color (phenol red turning yellow)?
- Decreased CO2
- Accumulation of lactic acid due to high metabolic activity or contamination
- Excess oxygen only
- High pH buffer addition
Correct Answer: Accumulation of lactic acid due to high metabolic activity or contamination
Q48. What is an organotypic culture?
- A single-cell suspension culture only
- A culture that preserves tissue architecture and cell–cell interactions ex vivo
- Culturing organisms on agar plates
- Only cryopreserved tissues
Correct Answer: A culture that preserves tissue architecture and cell–cell interactions ex vivo
Q49. Which precaution helps minimize cross-contamination between cultures in a biosafety cabinet?
- Working with multiple open flasks at once without organization
- Disinfecting surfaces, using sterile technique, and organizing workflow from clean to dirty
- Using the same pipette tips for different cultures
- Waving hands frequently inside the cabinet
Correct Answer: Disinfecting surfaces, using sterile technique, and organizing workflow from clean to dirty
Q50. Why are early documentation and labeling essential when creating primary cell banks?
- To increase storage costs
- To ensure traceability, reproducibility, and safe clinical or research use of primary cells
- Labeling is optional and can be omitted
- To reduce cell viability intentionally
Correct Answer: To ensure traceability, reproducibility, and safe clinical or research use of primary cells
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