Pharmaceutical Biotechnology MCQs on “Genetic Recombination – Gene Cloning”.
1. Why human cells are more preferred for the production of the recombinant protein?
a) Say in culturing
b) More sterility
c) Can be easily harvested
d) Post-translational modification
Answer: a
Clarification: Mammalian cells most commonly used for gene delivery. More importantly Human cells- allows the production of recombinant protein with authentic post-translational modifications. Products which are made by gene transfer are antibodies, hormones, growth factors, cytokines, and vaccines.
2. Which of the following will be a biological method for gene transfer?
a) Electroporation
b) Microinjection
c) Particle bombardment
d) Baculoviral vector system
Answer: d
Clarification: Gene transfer to animal cells has various biological and mechanical ways. The physical or mechanical ways are electroporation, microinjection, particle bombardment, sonoporation, laser-induced, bead transfection. The biological method is using various viral vectors for the transfer of DNA.
3. In which of this method electric field is applied for gene transfer?
a) Electroporation
b) Microinjection
c) Particle bombardment
d) Sonoporation
Answer: a
Clarification: In electroporation electric field is applied across the cells suspended in an electroporation cuvette. The high voltage for a few milliseconds is essential. Since this will create transient pores on the cell membrane which will get refilled again.
4. What should be the voltage/cm for electroporation to work?
a) 100 – 1000 V/cm
b) 10 – 100 V/cm
c) 10 – 50 V/cm
d) 10000 – 100000 V/cm
Answer: d
Clarification: Electroporation works by passing thousands of volts across a distance of one to two millimeters of suspended cells in an electroporation cuvette. 10000 – 100000 V/cm in a pulse lasting a few microseconds or milliseconds is essential. More than that the cells will die. This moderate voltage and time ratio should be maintained such that the pores of the cells are only opened.
5. Which of the following are the characteristics of electroporation?
a) Suspend the cells in an electroporation cuvette
b) Injecting the DNA into the cell
c) Also known as Biolistics
d) Usage of ultrasound
Answer: a
Clarification: Electropermealization also known as electroporation. It’s a technique where an electrical field is applied to cells so that the permeability of the cell membrane is increased. This allows chemicals, drugs, or DNA to be introduced into the cell.
6. Which of the following are the characteristics of microinjection?
a) Suspend the cells in an electroporation cuvette
b) Injecting the DNA into the cell
c) Also known as Biolistics
d) Usage of ultrasound
Answer: b
Clarification: Microinjection is the process where a micropipette is used to inject the foreign DNA straight into the nucleus of the cell. The cell will be held by a holding pipette. Then the researcher can easily inject the DNA into the cell. This method is widely used for various purposes.
7. Which of the following are the characteristics of particle bombardment?
a) Suspend the cells in an electroporation cuvette
b) Injecting the DNA into the cell
c) Also known as biolistics
d) Usage of ultrasound
Answer: c
Clarification: It was discovered by Prof Sanford at Cornell University (USA). It is also known as Biolistics (biological ballistics) since a gun is used in the process. It employs high-velocity microprojectiles to deliver substances like small drugs, DNA, etc into cells and tissues.
8. Which of the following are the characteristics of sonoporation?
a) Suspend the cells in an electroporation cuvette
b) Injecting the DNA into the cell
c) Also known as biolistics
d) Usage of ultrasound
Answer: d
Clarification: Sonoporation used ultrasound treatment for forming pores on the cell membrane. A microbubble which has the DNA will be provided with s=ultra sound along with the cells in which DNA has to be incorporated. The sound cause pores to be formed on the cell membrane and the bubble burst due to cavitation releasing the DNA into the solution.
9. Which of the following are the characteristics of laser-induced transfection?
a) Fin focus of laser light is used
b) Injecting the DNA into the cell
c) Also known as biolistic
d) Usage of ultrasound
Answer: a
Clarification: Laser-induced transfection is the use of a brief pulse of a focused laser beam. Here, DNA is mixed with the cells present in the culture. Then a fine focus of laser beam is passed on the cell surface which will form a small pore that will be sufficient for DNA uptake into the cells.
10. Which of the following are the characteristics of bead transfection?
a) Suspend the cells in an electroporation cuvette
b) Physically breaking the cells
c) Also known as Biolistic
d) Usage of ultrasound
Answer: b
Clarification: Bead transfection combines the principle of physically producing breaks in the cellular membrane using beads. In this method, the adherent cells are incubated for a brief period with glass beads in a solution containing the DNA. Suspending cells in electroporation cuvette is for electroporation. Biolistic is also known as particle bombardment. Ultrasound is used in sonoporation.
11. Which of the following do not incorporate in the genome and replicates in the cytoplasm?
a) Poxvirus
b) Baculovirus
c) Adenovirus
d) Retrovirus
Answer: a
Clarification: Poxvirus/ vaccinia virus does not get incorporated into the genome of the host cell. They reside in the cytoplasm and replicate in the cytoplasm. Thus, they help in transient transformation rather than permanent transformation. The genome size of pox/ vaccinia virus is 300 kb.
12. Bacterial gene delivery is known as _____________
a) Transduction
b) Bactofection
c) Infection
d) Conjugation
Answer: b
Clarification: Bacterial gene delivery is known as Bactofection and viral gene delivery is known as transduction. Bactofection is a method of direct gene transfer using bacteria into the target cell, tissue, organ or organism. Various bacterial strains used as vectors are L. monocytogenes, S. Typhimurium.
13. The efficiency of bead transfection is depended on the concentration of DNA in the solution.
a) True
b) False
Answer: a
Clarification: The efficiency of this rapid technique depends on the Concentration of DNA in a solution, the timing of the addition of DNA, size and condition of the beads and the buffers utilized. In this method, the adherent cells are incubated for a brief period with glass beads in a solution containing the DNA. Then the m=solution is mixed such that the beads collide and the cells coming in between the beads may get pores.
14. Electrochemotherapy is used to heal skin metastasis of squamous cell carcinoma.
a) True
b) False
Answer: a
Clarification: Chemotherapeutic surrounds the cells. When an electric current is passed the increased membrane, permeability allows access to the cytosol. This makes the pores to open. And the chemical can go inside the cells. The electric field is applied after injecting the chemotherapeutic inside the affected area.
15. Bead transfection is physically producing breaks in the cellular membrane using _____________
a) Beads
b) Electric current
c) Ultrasound
d) Laser light
Answer: a
Clarification: Bead transfection produces breaks in the cellular membrane using beads. The adherent cells, glass beads and solution containing the DNA are all incubated together. Then the solution is mixed such that the beads collide with each other so that any cells coming in between two beads will get a mechanical shock producing small pores.