Centrifugal force, types of centrifuges, applications etc.

1. CENTRIFUGATION
SUBMITTED BY-
1.Marzeea Ahmad Raka
2.Mir Tasnia Noshin
3.Suraiya Ahmed
4.Isfat Hasan Tomal
5.Nusrat Alam Mou
6.Atikur Rahman Nyeem

2. CONTENTS
 Definition of centrifugation
 History
 Principle of centrifugation
 Classification
 Operation
 Construction
 Application in Pharmaceutical industry
 Advantages & disadvantages
 Safety measures
 importance
 Summary

3. WHAT IS CENTRIFUGATION?
Centrifugation is one of the most important and widely applied
research cellular techniques in bio-chemistry and molecular biology,
pharmacy and in medicine.
 Centrifugation is a process which involves the use of the centrifugal
force for the sedimentation of heterogeneous mixtures with
a centrifuge.
 A centrifuge is a device that spins quickly to press objects outward
with centrifugal force.
 Centrifugal force is an apparent force that acts outward on a body
moving around a center, arising from the body's inertia.

4. CENTRIFUGATION
A centrifuge is used to separate particles or
even macro-molecules:
 Cells
 Subcellular components
 Proteins
 Nucleic acid
Basis of separation-
 Size
 Shape
 Density

5. HISTORY
English military engineer Benjamin Robins (1707–1751) invented a whirling
arm apparatus to determine drag.
In 1864, Antonin Prandtl proposed the idea of a dairy centrifuge to separate
cream from milk.
The idea was subsequently put into practice by his brother, Alexander
Prandtl, who made improvements to his brother's design, and exhibited a
working butterfat extraction machine in 1875.
The potential of the centrifuge in the laboratory setting was first exploited by
Friedrich Miescher. In 1869, Miescher used a crude centrifuge system to
isolate a cell organelle. This process led to the discovery of an important new
class of biological constituents, later to be known as nucleic acids.
The work of Miescher was quickly recognized and developed further by
others. In 1879, the first continuous centrifugal separator was demonstrated
by Gustaf de Laval. This development made the commercialization of the
centrifuge a possibility for the first time.

6. PRINCIPLE OF CENTRIFUGATION
Methodology-
 Utilizes density difference between the particles and the medium
in which these are dispersed
 Dispersed systems are subjected to artificially induced gravitational
fields.
 The centrifugal force causes the sedimentation of heavier solid
particles.

7. PRINCIPLE OF CENTRIFUGATION
A particle is subjected to centrifugal force when it is
rotated at high rate of speed. The centrifugal force, F is
defined by the equation-
F= mω2r
Where,
F= intensity of the centrifugal force
m= effective mass of the sedimenting particle
ω= angular velocity of rotation
r= distance of the migrating particles from the central
axis of rotation

8. PRINCIPLE OF CENTRIFUGATION
A more common measurement of F in terms of
the earths gravitation force , g, is relative
centrifugal force, RCF its defined by
RCF = (1.119 x 10-5 (rpm)2 (r)
This equation relates RCF to revolutions per
minute of the sample . Equation dictates that the
RCF on a sample will vary with r, the distance of
the sedimenting particles from the axis of rotation
. The RCF value is reported as “ a number times
gravity ,g .”

9. CLASSIFICATION OF CENTRIFUGATION

10. TYPES OF CENTRIFUGATION
Depend on the basis of :
-speed
-temperature

11. CONTINUED…….
There are various types of
centrifugation:
1.Differential Centrifugation
2. Isopycnic Centrifugation
3. Sucrose Gradient Centrifugation
4. Ultracentrifuges

12. DIFFERENTIAL CENTRIFUGATION
 Differential centrifugation is a common procedure
in microbiology and cytology
 Used to separate certain organelles from
whole cells for further analysis of specific parts of
cells
 Undergoes tissue disruption and cell lysis.
 Finally centrifugation

13. ISOPYCNIC CENTRIFUGATION
 In isopycnic separation, also called
equilibrium separation
 particles are separated solely on the
basis of their density.
 Particle size only affects the rate at
which particles move until their density
is the same as the surrounding gradient
medium
 Particles separate out according to their
buoyancy.
 used to isolate nucleic acids such as
DNA

14. SUCROSE GRADIENTCENTRIFUGATION
o A homogenate is placed on top of a
special medium e.g. sucrose
solution
o that progressively increases in
concentration density also
o when this sucrose gradient is
centrifuged at high speed each
particle in the homogenate will
move down in the tube and will
come to rest at the point in the
gradient where a density equals
that of the sucrose solution.
o often used to purify
enveloped viruses (with densities
1.1-1.2
g/cm³), ribosomes, membranes an
d cell organelles from crude
cellular extract.

15. ULTRACENTRIFUGE
The ultracentrifuge is
a centrifuge optimized for spinning
a rotor at very high speeds,
capable of generating acceleration
as high 19 600 km/s².
There are two kinds of
ultracentrifuges:
1.the preparative and
2. the analytical
ultracentrifuge.
Both classes of instruments find
important uses in molecular biology
, biochemistry, and polymer science

16. LABORATORY CENTRIFUGES
There are different types of laboratory
centrifuges:
 Micro Centrifuges
 Clinical Centrifuges
 Multipurpose High-Speed Centrifuges

17. INDUSTRIAL CENTRIFUGATION
Definition:
An industrial centrifuge is a machine used for fluid/particle
separation.
Types: Industrial centrifuges can be classified into 3 main
types:
(1)Filtration centrifuge: Those using perforated baskets,
which perform a filtration-type operation (work like a spin-
dryer). E.g. perforated basket centrifuge.
(2) Sedimentation centrifuge: Those with a solid walled
vessel, where particles sediment towards the wall under the
influence of the centrifugal force. E.g. Tubular bowl
centrifuge
(3) Continuous centrifuge: Those where a continuous
process or very high capacity is required.

18. 1. Perforated-basket centrifuges
(centrifugal filters)

19. Fig. Perforated basket
centrifuge

21. 2. Tubular-bowl centrifuges
(centrifugal sedimenters)

22. Fig: Tubular-bowl centrifuge

24. 3. Continuous centrifuge

25. It is fitted with a conical basket to allow continuous feeding
of a slurry and discharge of the separated solids.
Continuous operations are best suited for applications that
require high capacity and large (greater than 300 micron)
particle size. These centrifuges can provide excellent
washing and low final moisture.

26. Fabrication: Carbon fiber, Aluminum and
Titanium.

27. Fixed Angle Rotor
Fixed-angle rotors are the most ubiquitous rotors used
in centrifugation.
Angle: varies in 20 – 45⁰.
Speeds range: 0 - 1,000,000 × g
The cavities range: In volume from 0.2 mL to 1 L.
Factors determine the type:
 Desired g-force (RCF)
 Desired volume
Mechanism: The rotor begins to rotate
the solution in the tubes reorients.
This reorientation cause centrifugation.
Applications:
 Pellet separation
 Discard the. Excess debris
 Isopycnic separation of macromolecules
Fig: Fixed angle rotor

28. SWING BUCKET ROTOR
Ideal for separating large-volume
samples up to 12 L at low speeds.
Consists of three parts:
(1)The rotor body attaches to the
centrifuge drive and has four or six arms
to support the buckets
2) The buckets are placed onto the
arms of the rotor body
3) Pins are used to hold the buckets in
place.
Fig: Swing bucket rotor

29. MECHANISM
 Sample tubes are loaded into individual
buckets that hang vertically while the rotor is
at rest.
 When the rotor begins to rotate the buckets
swing out to a horizontal position. The longer
path length permits better separation of
individual particle types from a mixture.
 However, this rotor is relatively inefficient
for pelleting.

30. VERTICAL ROTOR
Tubes are held in vertical position during rotation.
Use: Ultracentrifugation for iso-pycnic separations,
specifically for the banding of DNA in cesium
chloride.
Mechanism: In this type of separation, the density
range of the solution contains the same density as
the particle of interest; thus the particles will orient
within this portion of the gradient. The particles to
orient at the proper position within the gradient
travel a short distance to pellet; therefore run time
is minimized.
Application: Include plasmid DNA, RNA, and
lipoprotein isolations.

32. ROTOR CARE
 Proper rotor care is essential for ensuring safety and
longevity. In addition to reducing the risk of accidents,
regular rotor maintenance can save time and money and
greatly extend rotor life span. All the rotors must be
protected by rinse, disinfectant and must be sterilize.

33. Applications in Industry
There are techniques on which the application of centrifuge
is based on-
preparative technique-

34. Application in Water Treatment

35. Pharmaceutical Industrial
Application
 Production of bulk drugs:
aspirin is separated from its mother liquor by
centrifugation.
 Biopharmaceutical analysis of drugs:
pharmacokinetic parameters and bioequivalence
studies.
 Determination of molecular weight of colloids:
Polymers, proteins and such macromolecules often
form colloidal dispersions. The molecular
weights of those molecules can be determined by
ultracentrifugation.

36. Pharmaceutical Industrial
Application
 Evaluation of suspensions and emulsions:
Centrifugation method is used as a rapid empirical test
parameter for the evaluation of suspension and emulsion.
 Production of biological products:
a) Separation of blood cells.
b) Purification of insulin by selectively
precipitating other fraction of proteins.
c) Separation of most of the proteinaceous drugs
and macromolecules.

37. Some Other Commercial
applications
 Large industrial centrifuges are commonly used
in water and wastewater treatment to dry sludge.
 In sugar industry to separate the sugar crystals
from the mother liquor .
 Standalone centrifuges for drying (hand-washed)
clothes – usually with a water outlet.
 Large industrial centrifuges are also used in the
oil industry to remove solids from the drilling
fluid.
 In soil mechanics.
 Centrifuges are used in the attraction Mission

38. ADVANTAGES AND
DISADVANTAGES:
Advantages:
 Centrifuges have a clean appearance and have little to no odor
problems.
 Not only is the device easy to install and fast at starting up
and shutting down, but also only requires a small area for
operation.
 They can be selected for different applications. .
 The device is simple to operate .
 Centrifuge has more process flexibility and higher levels of
performance.

39. DISADVANTAGES:
 The machine can be very noisy and can
cause vibration.
 The device has a high-energy consumption
due to high G-forces.
 High initial capital costs

40. SAFETY MEASURES
 A centrifuge user should strictly observe the following
precautions :
 Manufacturer’s manual should be strictly followed.
 Rotor should be stored in proper containers.
 Attention should be given to imbalance detectors.
 Rotor speed should not exceed the assigned speed.
 Lid of the rotor chamber should remain locked during
operation.
 To avoid the rotor failure, manufactures instructions
regarding rotor care and use should always be
followed.

41. SUMMARY
 The centrifugation is a modern & easy
technique of separation and sedimentation on
the basis of shape, size and density of
macromolecules and other particles.
 In the centrifugation there are different types
of forces are applied like as centrifugal force,
gravitational force and centripetal force etc.
and also different types of rotors are to be
used that is; Swinging Bucket Rotor and fixed
angle rotors at different RPM/RCF.

42. IMPORTANCE
Centrifugation play an important
role in both biological sectors as
well as industrial sectors.
In biological sector:
 Medical laboratories use
centrifuges to separate plasma
from heavier blood cells.
 Modern centrifuges can even
separate mixtures of different
sized molecules or microscopic
particles such as parts of cells.

43. Continued…..
In Industrial Sector:
 Cream separation from milk.
 Separating textiles
 Separating particles from an air flow using
cyclonic separation
 Clarification and stabilization of wine
 Centrifugation is the most common method
used for uranium enrichment.

44. REFERENCES
http://www.labmanager.com/lab-product/2010/05/evolution-of-the-lab-
centrifuge?fw1pk=2#.Viz08yskqxn
http://www.westernstates.com/continuous-centrifuges
https://en.wikipedia.org/wiki/Centrifuge
https://en.wikipedia.org/wiki/Differential_centrifugation
http://cellbiologyolm.stevegallik.org/node/74
 D. Rickwood and J. M. Graham (2001); Biological Centrifugation,
Springer Verlag; ISBN: 0387915761.
 D. Rickwood, T. Ford, J. Steensgaard (1994): John Wiley & Son Ltd.
ISBN: 0471942715.
 T. C. Ford and J. M. Graham (1991): An Introduction to Centrifugation,
BIOS Scientific Publishers, Ltd. ISBN 1 872748 40 6.
 http://www.thermoscientific.com/content/dam/tfs/LPG/LED/LED%20
Documents/Third-
Party%20Papers/Centrifuges/Centrifuge%20Rotors/Ultracentrifuge%20R
otors/D20940~.pdf