1. Who invented centrifugation?
A) GG Stokes
B) Antonin Prandtl
C) Louis Pasteur
D) Johnstone
2. Which of the following is/are appropriate care and maintenance of centrifuges?
i) Proper balancing of centrifuge tubes.ii) Avoid long time exposure of the rotors to alkaline solution and acidic buffers.
iii) Cleaning centrifuges and rotors with coarse brushes and then wash them with distilled or deionised water after every run.
iv) For overnight storage, the rotors are left upside down and then positioned in a safe and dry place.
A) i, ii, iii only.
B) i, ii, and iv only.
C) ii, iii and iv only.
D) All of these.
3. Which of the following used as media for density gradient?
A) Ficoll
B) Luria broth
C) PEG
D) Agarose
4. Which of the following is used in uranium enrichment?
A) Tubular centrifuge
B) Gas centrifuge
C)Sisk stack Centrifuge
D) Zippe type Centrifuge
5. What are rate zonal Centrifugation?
A) based on separation of particles on size
B) based on separation of particles on solubility
C)based on separation of particles by density
D) based on separation of particles by mass
6. What is the Principle of centrifugation?
A) evaporation principle
B)Sedimentation principle
C)Filtration principle
D) size reduction principle
7. At what speed do you centrifuge blood?
A) 3000-3200 RPM
B) 4000 RPM
C) 2200-2500RPM
D) 1000-1500 RPM
8. What is the applied centrifugal field at a point equivalent to 5 cm from the centre of rotation and an angular velocity of 3000 rad s -1?
A) 4.5x107 cm s -2
B) 4.7x105 cm s -2
C) 1.5x107 cm s -2
D) 1.5x105 cm s
9.SARS-CoV-2 that causes COVID-19 is commonly isolated using
A) Chromatography
B) Density gradient centrifugation
C) Electro focusing
D) Electro fishing
10. Rate zonal centrifugation separates particles that differ in:
A) Size but not density
B) Density but not in size
C) Both size and density
D) Neither size nor density
11. After centrifugation of milk, the supernatant is
A) Water
B) Whey
C) Fat
D) Casein
12. Which of the following centrifugation is used to separate certain organelles from whole cell?
A) Differential centrifugation
B) Rate zonal centrifugation
C) Isopycnic centrifugation
D) None of these
Learn more: Biophysics and Principle of Instrumentation MCQ
Answers:
1. A) GG Stokes
2. B) i, ii, and iv only.
3. A) Ficoll
4. B) Gas centrifuge
5. A) based on separation of particles on size
6. B)Sedimentation principle
7. C) 2200-2500RPM
8. A) 4.5x107 cm s -2
The centrifugal field G, G = ω2 r,
G = (3000)2 × 5 cm s-2
= 4.5 × 10-7 cm s-2.
9. B) Density gradient centrifugation
10. A) Size but not density
11. B) Whey
12. A) Differential centrifugation
