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10.6 Cytotoxicity & Functional Assays β Test 1
Q1. The classic chromium-release assay measures cytotoxicity by detecting:β Release of β΅ΒΉCr from labelled target cells that are killed
Q2. A cytotoxicity assay using effector and target cells is commonly used to measure the activity of:β Cytotoxic T cells and NK cells
Q3. The lymphocyte proliferation (transformation) assay assesses immune function by measuring:β Lymphocyte division in response to a mitogen or antigen
Q4. Mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A) are used because they:β Non-specifically stimulate many T cells to proliferate
Q5. Antibody-dependent cell-mediated cytotoxicity (ADCC) assays measure killing of:β Antibody-coated target cells by effector cells (e.g. NK cells)
Q6. A non-radioactive alternative to the chromium-release assay can use:β Release of a cytoplasmic enzyme (e.g. LDH) or fluorescent dyes from killed cells
Q7. The mixed lymphocyte reaction (MLR) is used to:β Assess T-cell alloreactivity (e.g. in transplant compatibility)
Q8. The intracellular cytokine staining assay (by flow cytometry) measures:β Cytokines produced inside individual stimulated T cells
Q9. A complement-dependent cytotoxicity (CDC) assay measures:β Antibody- and complement-mediated lysis of target cells
Q10. The phagocytosis assay evaluates the ability of cells to:β Engulf particles or microbes (e.g. labelled bacteria/beads)
Q11. The nitroblue tetrazolium (NBT) / dihydrorhodamine (DHR) test assesses phagocyte function by measuring:β The respiratory (oxidative) burst
Q12. CFSE dye dilution is used in flow cytometry to track:β Successive cell divisions (proliferation)
Q13. NK-cell activity is commonly assessed using which target cell line?β K562 (MHC-class-I-low)
Q14. A skin test (e.g. tuberculin) is an in vivo functional assay that detects:β Delayed-type (type IV) cell-mediated immunity
Q15. In a cytotoxicity assay, varying the effector-to-target (E:T) ratio allows:β Assessment of how killing changes with effector-cell number
Q16. ELISpot, a functional assay, is especially useful for measuring:β The frequency of antigen-specific cytokine-secreting T cells
Q17. A viability dye such as trypan blue distinguishes live from dead cells because it:β Enters and stains only cells with damaged membranes (dead cells)
Q18. Functional immune assays are clinically important because they:β Reveal whether immune cells actually work, not just whether they are present
Q19. In cytotoxicity assays, 'percent specific lysis' is calculated by correcting measured release for:β Spontaneous release and maximal (total) release controls
Q20. Match each functional assay with what it measures and select the correct option.β A-ii, B-iv, C-i, D-iii