Characterization of cultured cells MCQs With Answer

Characterization of cultured cells MCQs With Answer

This quiz collection is designed for M.Pharm students to reinforce advanced concepts in characterization of cultured cells, a key topic in Modern Bio-Analytical Techniques (MPA 202T). Questions cover morphology, viability and proliferation assays, molecular and immunological identification, contamination detection, authentication, functional assays (metabolism, senescence, clonogenicity), and instrumentation such as flow cytometry and live-cell analyzers. Each question emphasizes practical interpretation of results and selection of appropriate techniques for specific experimental problems. Use these MCQs to test conceptual clarity, troubleshooting skills and readiness for laboratory decision-making in cell culture-based research and quality control.

Q1. Which assay specifically measures mitochondrial metabolic activity by conversion of a tetrazolium salt into a colored formazan product and is commonly used to infer cell viability?

• Trypan blue exclusion assay
• MTT reduction assay
• Clonogenic assay
• BrdU incorporation assay

Correct Answer: MTT reduction assay

Q2. In flow cytometry, forward scatter (FSC) and side scatter (SSC) primarily provide information about which cellular features?

• FSC indicates granularity and SSC indicates DNA content
• FSC indicates cell size and SSC indicates internal complexity or granularity
• FSC indicates fluorescence intensity and SSC indicates cell viability
• FSC and SSC both measure surface marker expression

Correct Answer: FSC indicates cell size and SSC indicates internal complexity or granularity

Q3. Which method provides definitive cell line authentication by comparing short tandem repeat (STR) loci profiles?

• Karyotyping
• Whole-transcriptome sequencing
• Short tandem repeat (STR) profiling
• Mycoplasma PCR

Correct Answer: Short tandem repeat (STR) profiling

Q4. For detecting mycoplasma contamination in a cell culture where rapid sensitivity and species-level identification are required, which technique is most appropriate?

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

Correct Answer: PCR-based mycoplasma detection

Q5. Which assay directly measures DNA synthesis as an indicator of proliferation by incorporating a thymidine analog that can be detected immunochemically?

• MTT assay
• BrdU incorporation assay
• Annexin V staining
• Senescence-associated β-galactosidase staining

Correct Answer: BrdU incorporation assay

Q6. Which marker is most widely used to identify proliferating cells in fixed tissue sections by immunostaining?

• p21
• Ki-67
• β-galactosidase
• Caspase-3

Correct Answer: Ki-67

Q7. When assessing transfection efficiency of a plasmid expressing GFP in adherent cells, which approach gives the most direct quantitative measure?

• Counting GFP-positive colonies after antibiotic selection only
• Flow cytometry quantification of GFP-positive cells
• Western blot for GFP without normalization
• MTT assay of transfected population

Correct Answer: Flow cytometry quantification of GFP-positive cells

Q8. Which technique is best for determining relative mRNA expression levels of a gene of interest in cultured cells with high sensitivity and quantitative output?

• Conventional PCR with gel electrophoresis
• Quantitative real-time PCR (qRT-PCR)
• Immunocytochemistry
• MTT reduction assay

Correct Answer: Quantitative real-time PCR (qRT-PCR)

Q9. Which assay is used to detect senescent cells by exploiting increased lysosomal β-galactosidase activity at pH 6.0?

• Annexin V/PI staining
• Senescence-associated β-galactosidase (SA-β-gal) staining
• Trypan blue exclusion assay
• BrdU incorporation assay

Correct Answer: Senescence-associated β-galactosidase (SA-β-gal) staining

Q10. Which contamination in cell culture is most likely to alter gene expression and metabolism subtly and is often undetected by light microscopy?

• Fungal contamination
• Bacterial contamination visible as turbidity
• Mycoplasma contamination
• Yeast contamination with floating colonies

Correct Answer: Mycoplasma contamination

Q11. In immunocytochemistry to identify a membrane protein, which control is essential to confirm specificity of the antibody staining?

• Omitting primary antibody (no-primary control)
• Performing MTT assay in parallel
• Using a different cell line without staining
• Measuring cell size by flow cytometry

Correct Answer: Omitting primary antibody (no-primary control)

Q12. Which technique allows real-time measurements of cellular respiration and glycolysis to characterize metabolic phenotype of cultured cells?

• Seahorse extracellular flux analysis
• Colorimetric ATP assay only
• BrdU incorporation
• Trypan blue exclusion

Correct Answer: Seahorse extracellular flux analysis

Q13. For evaluating the long-term clonogenic survival after radiation or drug treatment, which assay is most appropriate?

• Short-term MTT assay
• Colony formation (clonogenic) assay
• Flow cytometric cell cycle analysis
• Annexin V apoptosis assay

Correct Answer: Colony formation (clonogenic) assay

Q14. Which method is preferred to confirm pluripotency of human embryonic stem cells by checking expression of core transcription factors?

• Karyotype analysis
• Immunostaining or qRT-PCR for OCT4, SOX2 and NANOG
• MTT viability assay
• Mycoplasma PCR

Correct Answer: Immunostaining or qRT-PCR for OCT4, SOX2 and NANOG

Q15. When performing flow cytometry with multiple fluorophores, which procedure is critical to correct for spectral overlap between channels?

• Using only isotype controls
• Using compensation controls and single-stained controls
• Increasing laser power indiscriminately
• Reducing sample concentration to minimal levels

Correct Answer: Using compensation controls and single-stained controls

Q16. Which assay is most suitable to quantify dead cells that have lost membrane integrity in a mixed population?

• Annexin V positive / Propidium iodide negative gating
• Propidium iodide (PI) staining or 7-AAD exclusion
• BrdU incorporation assay
• SA-β-gal staining

Correct Answer: Propidium iodide (PI) staining or 7-AAD exclusion

Q17. Which approach is best to detect and quantify endotoxin contamination in cell culture reagents that can affect cell behavior and assay results?

• Limulus Amebocyte Lysate (LAL) assay
• Gram staining of reagents
• PCR for bacterial 16S rRNA
• Trypan blue exclusion

Correct Answer: Limulus Amebocyte Lysate (LAL) assay

Q18. To analyze cell cycle distribution (G0/G1, S, G2/M) quantitatively by DNA content, which staining combined with flow cytometry is commonly used?

• Annexin V staining
• Propidium iodide (PI) staining after RNase treatment
• MTT staining
• Immunocytochemistry for Ki-67 only

Correct Answer: Propidium iodide (PI) staining after RNase treatment

Q19. Which technique would most directly reveal chromosomal abnormalities such as translocations or aneuploidy in cultured cells?

• qRT-PCR for housekeeping genes
• Conventional G-banded karyotyping
• MTT reduction assay
• Flow cytometric measurement of FSC/SSC only

Correct Answer: Conventional G-banded karyotyping

Q20. When establishing a 3D spheroid model to study drug penetration and response, which characteristic of spheroids most closely mimics solid tumor microenvironments?

• Uniform single-cell suspension
• Presence of gradients (oxygen, nutrients) and proliferative zones
• Absence of extracellular matrix
• Complete lack of hypoxic regions

Correct Answer: Presence of gradients (oxygen, nutrients) and proliferative zones

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