This set of Cytogenetics Multiple Choice Questions on “Flow Cytometry and Cell Sorting”.
1. Flow cytometry uses_____________
A. Heavy isotope
B. Radioactive elements
C. Immunological techniques
D. Energy content
Answer: C
Clarification: The process of flow cytometry is based on immune fluorescence where a laser is used to irradiate the fluorescent particle bound to a particle that determines its fete.
2. In flow cytometry which of the combination is impossible?
A. Both the labeled antigens in same particle
B. None of the labeled antigens on a particle
C. One of the labeled antigen
D. All can be true
Answer: D
Clarification: In flow cytometry we can have all the above combinations. The cells can even be sorted according to the antigens present on them.
3. In a flow cytometer the particles are analyzed all at a time.
A. True
B. False
Answer: B
Clarification: It is ensured by dilution that in a flow cytometer the particles pass in a single file. Then they are individually identified and sorted.
4. In human normal B and T cells develop the CDC4+ and CDC8+ first and then they differentiate to CDC4+ CDC- and CDC4- CDC+. If there is a defect in development which quadrant in the flow cytometer graph will show more density?
A. 1
B. 2
C. 3
D. 4
Answer: B
Clarification: Quadrant 2 is the part of the graph where we see both the labels being positive. So in this case mal developement will mean that this quadrant will have higher density.
5. How are the cells sorted?
A. By dilution plating until there are only single cell in each well of microtitre plate
B. By the differential weight
C. By electrostatic force
D. By magnetic force
Answer: C
Clarification: As the cells exit the nozzle of the flow cytometer a small amount of charge is added to the droplet. Then it passes between the two places which induce the droplet to be properly separated depending on its label.
6. In a flow cytometer you will see the cells lacking both the labels in ____________ quadrant.
A. 1st
B. 2nd
C. 3rd
D. 4th
Answer: C
Clarification: In the 1st quadrant and 4th quadrant one of the two labels are active. In the 2nd both are active and in the 3rd none of the labels are present on the molecule.
7. Which fluorescent dye can be used for red fluorescence?
A. Rhodamine
B. Fluorescein
C. Carmine
D. DAPI
Answer: A
Clarification: The Rhodamine gives red fluorescence while the fluorescein gives a green fluorescence. Carmine is a red dye that is used in food but it’s not used for immunological methods. DAPI stains the nucleus blue.
8. Which of the following drugs effect caspases?
A. Oblimerson
B. Pikan083
C. Tenovin
D. Apoptin
Answer: D
Clarification: Apoptin, a caspase-inducing agent, has been reported to induce apoptosis in malignant but not in normal cells. Small molecules caspase activators are peptides which contain the arginine-glycine-aspartate motif. They induce activation of procaspase 3.
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