Centrifugation

Question 1

The most popular technique used in biological sciences for separation of particles/microorganisms by centrifuge

Answer 1

Centrifugation

Question 2

a device for separation of microorganisms from the suspended fluid using centrifugal force (g-force)

Answer 2

Centrifuge

Question 3

In a solution, _____ particles sediment in influence of gravitational field

Answer 3

higher density

Question 4

When centrifugal force applied by the centrifuge, the particles _____

Answer 4

move faster

Question 5

Expressed as a multiple of acceleration (G) due to gravity (g)

Answer 5

Relative Centrifugal Force

Question 6

When a biological sample moves in centrifuge, it experiences an _____

Answer 6

Outward centrifugal force

Question 7

Rate of sedimentation of biological sample is dependent on the _____

Answer 7

Applied centrifugal force

Question 8

The applied centrifugal force is determined by the _____ of the particle from the axis of rotation

Answer 8

Radial distance

Question 9

Can be defined as numbers of revolutions (cycles) per second

Answer 9

Frequency

Question 10

the ratio of the centrifugal acceleration (G) and gravitational acceleration (g)

Answer 10

Relative centrifugal force (RCF)

Question 11

Sedimenting particles have only short distance to travel before pelleting, has a shorter run time, and is the most widely used rotor type

Answer 11

Fixed angle rotor

Question 12

Longer distance of travel may allow better separation, such as in density gradient centrifugation

Answer 12

Swinging bucket rotor

Question 13

Easier to withdraw supernatant without disturbing pellet

Answer 13

Swinging bucket rotor

Question 14

Super speed centrifuge

Answer 14

High-speed centrifuges

Question 15

Which centrifuge type can handle larger sample volumes, from a few tens of mL to several L?

Answer 15

High-speed centrifuge

Question 16

The rotors may come with different adapters to hold various sizes of test tubes, bottles, or microliter plates

Answer 16

High-speed centrifuge

Question 17

RPM of High-speed centrifuge

Answer 17

3000 rpm (1500-20000 rpm)

Question 18

Maximum angular velocity of ultracentrifuge

Answer 18

70000 rpm (65000 rpm)

Question 19

Can be used in the study of membrane fractionation

Answer 19

Ultracentrifuge

Question 20

Can separate molecules in batch or continuous flow systems

Answer 20

Ultracentrifuge

Question 21

During the run of this centrifuge, the particles or molecules will migrate through the test tube at different speeds depending on their physical properties and the properties of the solution

Answer 21

Ultracentrifuge

Question 22

A centrifuge that is normally refrigerated and is often used for research applications

Answer 22

High-speed centrifuge

Question 23

Expensive and requires a special rotor and the care in use balance is critical

Answer 23

Ultracentrifuge

Question 24

Used to process small volumes of biological molecules, cells, or nuclei

Answer 24

Microcentrifuge

Question 25

Volume of tubes that holds the liquid of microcentrifuge

Answer 25

0.5-2mL

Question 26

Maximum angular speed of microcentrifuge

Answer 26

12000-13000 rpm

Question 27

Small enough to fit on a table-top and have rotors that can quickly change speeds

Answer 27

Microcentrifuge

Question 28

Simple centrifuges that are used to separate erythrocytes, blood samples, coarse precipitates, and cells

Answer 28

Small bench/laboratory centrifuge

Question 29

Speed range and centrifugal force of small bench centrifuge

Answer 29

4000-6000 rpm and 3000-7000 g

Question 30

Volume of liquid processed by small bench centrifuge and how much time does it take

Answer 30

250 mm3 - 1.5 cm3 , for 1-2 min

Question 31

Common use of microcentrifuge

Answer 31

biochemistry/ molecular biology/ biological labs

Question 32

Common use of small bench top centrifuge

Answer 32

clinical labs (blood/ plasma/ serum/ separation)

Question 33

How much tubes is the approximate capacity of small bench top centrifuge?

Answer 33

100 tubes

Question 34

How much is the maximum generated force of microcentrifuge?

Answer 34

15000 x g

Question 35

Helps in preserving the morphology and activity of subcellular fractions

Answer 35

Sucrose and Ficoll

Question 36

Useful in isopycnic density gradient centrifugation technique

Answer 36

Cesium chloride and Potassium bromide

Question 37

Because of its low osmolarity, low viscosity and large particle size, is suitable for separating cells, bacteria, viruses, and subcellular organelles

Answer 37

Percoll

Question 38

For the isolation of membrane fractions by floatation

Answer 38

Metrizamide and Nycodenz

Question 39

For cell fractionation

Answer 39

Renografin

Question 40

Centrifugal force required for nuclei

Answer 40

800 - 1000 g

Question 41

Centrifugal force required for mitochondria

Answer 41

20000 - 30000 g

Question 42

Centrifugal force required for chloroplasts

Answer 42

20000 - 30000 g

Question 43

Centrifugal force required for lysosomes

Answer 43

20000 - 30000 g

Question 44

Centrifugal force required for microbodies

Answer 44

20000 - 30000 g

Question 45

Centrifugal force required for RER (microsomes)

Answer 45

50000 - 80000 g

Question 46

Centrifugal force required for plasma membranes, SER membranes

Answer 46

80000 - 100000 g

Question 47

Centrifugal force required for free ribosome particles

Answer 47

150000 - 300000 g

Question 48

Typical separation method for DNA and RNA and its most appropriate rotor

Answer 48

CaCl gradient, 4000000xg; Ethidium Bromide staining ; vertical and fixed angle

Question 49

Typical separation method for viruses and its most appropriate rotor

Answer 49

Sucrose gradients, 100000xg ; swinging bucket

Question 50

Typical separation method for proteins and its most appropriate rotor

Answer 50

Rate-zonal separation, 600000xg ; fixed angle

Question 51

Typical separation method for cells and organelles and its most appropriate rotor

Answer 51

Differential pelleting-low speeds for cells; high speeds-smaller organelles ; fixed angle

Question 52

Used to measure the sedimentation velocity in an ultracentrifuge and to determine molecular weight by substitution in an equation

Answer 52

Svedberg unit

Question 53

Relationship between RPM and RCF

Answer 53

Direct

Question 54

Relationship between G and size particles

Answer 54

Inverse

Question 55

For swinging bucket type, what is the relationship between distance and separation level?

Answer 55

Direct (more distance means better separation)

Question 56

A process of combination of sediments after centrifugation

Answer 56

Pelleting

Question 57

A quality control instrument that checks the speed of centrifuge (in RPM)

Answer 57

Tachometer