Centrifugation is one of the most important and widely applied research cellular, techniques in bio-chemistry and molecular biology, pharmacy and in medicine.

1. Asifur Rahman
01747137920
Department of Pharmaceutical Sciences,
NSU

2. INTRODUCTION: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 in which
Mixture are separated using the
centripetal force generated by spinning
in a centrifuge. More dense components
of the mixture move away from the
axis of the centrifuge while less
dense components of the
mixture move
towards the axis.

3. A particle,whether it is precipitate,a macromolucle or
cell organelle when rotated at high speed is subjected
to a centrifugal force. Centrifugal force is defined as
F=mw2r
Where
F=intensity of centrifugal force
m= effective mass of sedimenting particle
w= angular velocity of rotation
r = distance of migrating particles from central
axis of rotation
CENTRIFUGATION:

4. Principle of
Centrifugation

5. Principles of Centrifuges
Basis of Separation :
 Size
 Shape
 Density
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.

6. Centrifugal Force :
Consider a body of mass m rotating in a circular
path of radius r at a velocity v. The force acting
on the body in a radial direction is given by:
F =
Here, F = centrifugal force
m = mass of the body
v = velocity of body
r = radius of circle of rotation
mv 2
r
The same body will be acted upon by a gravitational force. It can be
expressed as:
G = mg
where, G = gravitational force , and
g = gravitational constant

7. The centrifugal effect is the ratio of the two forces, so that:
C = F / G
= mv2 / mgr
= v2 / gr
But,
v = 2πrn
Where, n = speed of rotation.
So,
F / G = (2πrn)2 / gr
= 4π2r2n2 / gr
= 2 π2n2d / g ……………(1)
Where, d = diameter of rotation.
Continued…..

8. The gravitational constant has a value of 9.807 m/s2, so that equation (1) may be
simplified to:
Centrifugal effect = 2.013 n2d
Provided that , n is expressed in s-1 and d is in meter.
From the equation, it can be drawn that the centrifugal effect is proportional
directly to the diameter, but is proportional to the square of the speed of the
rotation. Thus, if it is necessary to increase the centrifugal effect, it is of greater
advantages to use a centrifuge of the same size at a higher speed, rather than use
a larger centrifuge at the same speed of rotation.
Continued…..

9. Classification of
Centrifugation

10. Types of Centrifuges
Centrifuges can be classified on the basis of :
• speed
• temperature
• use
On the basis of speed:
The "speed" of a centrifuge is measured in rotation per minute,
or rpm. Centrifuges are generally divided into 3 categories
based on their maximum attainable speed:
Low-speed : to maximum of 5 x 103 rpm.
High-speed : to maximum of 2 x 104 rpm.
Ultracentrifuges : to maximum of 105 rpm.

11. On the basis of temperatur :
Refrigerated centrifuges have a built-in refrigeration unit
surrounding the rotor, with a temperature sensor and thermostat
permitting selection of a particular temperature or a permissible
temperature range that is maintained during centrifugation. Many
biological samples are temperature sensitive, and centrifugation in
the cold (1-4oC) is frequently required.
Centrifuges that are not refrigerated are normally used at whatever
temperature the room they are in happens to be. This is typically
described in research reports as "room temperature" or “ambient
temperature”.

12. On the basis of use :
Centrifuges
Laboratory equipment
1. Swing-out arm type
2. Angle type
3. Ultracentrifuge
Commercial equipment
Perforated bowl types Sedimentation centrifuges
Batch
1. Top driven
2. Under driven
Semi continuous Continuous or
Super centrifuge
Vertical
1. Simple bowl
2. Bowl with plates
Horizontal
continuous
decanters

13. Types Of Centrifugation
There are various types of
centrifugation:
1. Differential Centrifugation
2. Isopycnic Centrifugation
3. Sucrose Gradient
Centrifugation
4. Ultracentrifuges

14. 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. In the process, a tissue sample is
first homogenized to break the cell membranes and mix up
the cell contents. The homogenate is then subjected to
repeated centrifugations, each time removing the pellet and
increasing the centrifugal force. Finally, purification may be
done through equilibrium sedimentation, and the desired
layer is extracted for further analysis.

15. Isopycnic Centrifugation:
Isopycnic centrifugation, also known as density
gradient centrifugation or equilibrium
sedimentation is a technique used to separate
molecules on the basis of buoyant density. (The
word "isopycnic" means "equal density".) Typically,
a "self-generating" density gradient is established
via equilibrium sedimentation, and then analyze
molecules concentrated as bands where the
molecule density matches that of the surrounding
solution.
It is often used to isolate nucleic acids such as
DNA.

16. Sucrose Gradient
Centrifugation:
Sucrose gradient centrifugation is a type
of centrifugation often used to purify
enveloped viruses (with densities 1.1-1.2
g/cm³), ribosomes, membranes and cell organelles
from crude cellular extract. This method is also
used to purify exosomes. There are two methods -
equilibrium centrifugation and non-equilibrium
centrifugation.

17. Ultracentrifuge
The ultracentrifuge is a centrifuge optimized for
spinning a rotor at very high speeds, capable of
generating acceleration as high
as 2 000 000 g (approx. 19 600 km/s²). There are two
kinds of ultracentrifuges, the preparative and the
analytical ultracentrifuge. Both classes of
instruments find important uses in molecular biology
, biochemistry, and polymer science.

18. There are different types of laboratory
centrifuges:
Micro Centrifuges:
Devices for small tubes from 0.2 ml to 2.0 ml
(micro tubes), up to 96 well-plates, compact
design, small footprint; up to 30,000 g
Clinical Centrifuges:
Moderate-speed devices used for clinical
applications like blood collection tubes
Multipurpose High-Speed Centrifuges:
Devices for a broad range of tube sizes, high
variability, big footprint

19. INDUSTRIAL CENTRIFUGE
Definition:
An industrial centrifuge is a machine used for fluid/particle separation.
Types:
Industrial centrifuges can be classified into two main types:
1.sedimentation centrifuge and
2. filtering centrifuges.

20. TYPES:
Sedimentation centrifuge:
Sedimentation centrifuges use centrifugal force to separate solids from
liquids as well as two liquids with different specific gravities.
Sedimentation centrifuges include decanter, disk-stack, solid-bowl
basket and tubular bowl centrifuges.
Filtering Centrifuges:
Filtering centrifuges use centrifugal force to pass a liquid through a
filtration media, such as a screen or cloth while solids are captured by
the filtering media.
Filtering centrifuges primarily deal with perforate basket, pusher and
peeler centrifuges.

21. CONSTRUCTION:
The main parts of the Centrifuge are Bearing and Shaft,
Basket, Drive and Brake
 BEARING AND SHAFT:
The Heavy duty bearing is chosen to withstand vibratory load
and centrifugal force and the shaft is made up of suitable
material and duly balanced independently without the basket
for higher accuracy.
 BASKET:
The basket is made up of adequate thickness so as to
withstand the loads caused by the centrifugal forces .
 DRIVE:
The drive consists of Motor mounted at the basket casing
driven through V belt with provision of the tensioning the
belts.
 BRAKE:
The Centrifuge are fitted with external shoe brakes with brake
liners.

22. ADVANTAGES AND DISADVANTAGES:
 Advantages:
• Centrifuges have a clean appearance and have little to no odour 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 machine can operate with a higher capacity than smaller machines.
 The device is simple to operate .
 Centrifuge has more process flexibility and higher levels of performance.
• Disadvantages:
 The machine can be very noisy and can cause vibration.
 The device has a high-energy consumption due to high G-forces.
 The decanter centrifuge has high equipment capital costs.

24.  Production of bulk drugs:
aspirin is separated from its mother liquor by centrifugation.
 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.
 Biopharmaceutical analysis of drugs:
Centrifugation is used for separating the drugs which is essential for
the evaluation of pharmacokinetic parameters and bioequivalence
studies.
Application of Centrifuges

25. Evaluation of suspension and emulsion:
 Centrifugation method is used as a rapid empirical test
parameter for the evaluation of suspension and emulsion.
 Ultracentrifugation are used for determination of molecular
weight of serum albumin, insulin etc.
 Isolation of bacterial cells, fungal and actinomycete
mycelium and fermentation media is facilitated by
laboratory centrifuge.
 Removal of finely suspended solid matter (clarification) from
aqueous or oily materials.
 Ultracentrifuge can be used for separation of virus particles
which has potential industrial applications.

26. HALCINONIDE CREAM
IDENTIFICATION
 2 mg halcinonide cream in a 50 mL centrifuge tube
 15 ml water added and shaked to disperse
 20 mL of chloroform added and shake for 5 minutes
 Cooling & Centrifugation
 Transfer the chloroform layer in a conical flask
 Repeat the process
 ASSAY: Chromtography is used .

27. SULFISOXAZOLE ACETYL
ORAL SUSPENSION
IDENTIFICATION
 centrifuge a portion of it and separate the solid by several
portion of water
 re crystalized from hot alcohol and crystals are used for
identification
ASSAY
 Measured volume of oral suspension equivalent to 1 gram
sulfixazole
 Mixed with 40 mL of HCl and 25 mL glacial acetic acid
 swirl to dissolve and add 100 mL water
 Nitrite titration
 0.1 M sodium nitrite equivalent to 26.73mg sulfisoxazoleReferences: 1.USP &
2. Centrifugation in biology and medical sciences by Philip Sheeler

28. SUMMARY

29. CENTRIFUGATION
The centrifuge is an instrument used in nearly every
research lab across the globe. Centrifugation is the
process by which a centrifuge is used to separate
components of a complex mixture. By spinning
laboratory samples at very high speeds, the
components of a given mixture are subjected to
centrifugal force, which causes more dense particles to
migrate away from the axis of rotation and lighter ones
to move toward it. These particles can sediment at the
bottom of the tube into what’s known as a pellet, and
this isolated specimen, or the remaining solution, the
supernatant, can be further processed or analyzed.

30. Centrifugation in biological research
The process which involves are:
Micro centrifuges
High speed centrifuges
Fractional process
Ultracentrifuges
In pharmaceutical preparation,
centrifugation method is used as a rapid
empirical test parameter for the evaluation
of suspension and emulsion.

31. IMPORTANCE
Centrifugation has huge importance in both
biological sectors as well as industrial
sectors.
In biological sectors-
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

32. In industrial sectors-
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

33. Thank You
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