1. Electrophoresis is the migration of charged particles through a conductive medium such as a gel under the influence of an electric field. It is used to separate biomolecules like proteins and DNA based on their size and charge. 2. An electrophoretic system consists of two electrodes (anode and cathode) connected by an electrolyte medium. Charged particles migrate at different velocities depending on their size, shape, and charge, allowing for separation. 3. Factors like pH, ionic strength, voltage, and temperature influence electrophoretic separation. Applications include DNA analysis, antibiotic and vaccine testing, and studying protein-antibody interactions.

1. GROUP 4 MEMBERS
STUDENT NAME STUDENT NUMBER
NABUCHA OLIVER 1901200222
ALULE ALEX 1801200
ODONGO J JUDE 1901200070

2. ELECTROPHORESIS
Introduction;
Electrophoresis Is the motion of dispersed particles relative to
a fluid under the influence of a spatially uniform electric field. Or
It’s the migration of charged solutes or particles in a liquid
medium under the influence of an electric field.
Some other common terms used include;
 Cataphoresis; Electrophoresis of positively charged particles.
 Anaphoresis; Electrophoresis of negatively charged particles.
 Iontophoresis: This is limited to the migration of small ions

3. Con’t
 Leading electrolyte solution: Contains ions that are faster
than any in the sample.
 Trailing solution: Ions that are slower than any in the sample.
 Electrophoretic: The rate of migration (cm/s) per unit field
strength. Expressed by symbol μ
 Gel; used as a medium for the separation of macromolecules.

4. AN ELECTROPHORETIC SYSTEM
Consists of two electrodes of opposite charge (anode, cathode).
Connected by a conducting medium called an electrolyte.
The separation effect on the ionic particles results from
differences in their velocity (v), which is the product of the
particle's mobility (m) and the field strength (E)

5. Con’t
The mobility (m) of an ionic particle is determined by particle
size, shape, and charge, and the temperature during the
separation, and is constant under defined electrophoretic
conditions.
Electrophoretic conditions are characterized by the electrical
parameters (current, voltage, power), and factors such as ionic
strength, pH value, viscosity, pore size, etc., which describe the
medium in which the particles are moving.

6. Con’t

7. The buffer solution
 It maintains the pH of the solution.
 It carries and influences the applied current and also determines the
direction and rapid speed of molecules migration.
 Determines the electrical charge on the solute.
 Depending on the pH of the buffer, proteins in a sample will carry different
charges.
 At the pI (isoelectric point) of a specific protein, the protein molecule
carries no net charge and does not migrate in an electric field.
 At pH above the pI, the protein has a net negative charge and migrates
towards the anode. At pH below the pI the protein obtains a net positive
charge on its surface and migrates towards the cathode.

8. THE BUFFER IONIC STRENGTH
As ionic strength of buffer increases;
 Proportion of current carried by buffer increases.
 Proportion of current carried by the sample decreases and
hence showing decrease in sample rate of migration.
High Ionic strength increases the overall current and hence heat
is produced.

9. Con’t
As Ionic strength of buffer decreases;
 Proportion of current carried by buffer
decreases.
 Proportion of current carried by the sample
increases and hence showing increase in
sample rate of migration.
Low Ionic strength also decreases the overall
current and hence decrease in heat production.

14. IMMUNOELECTROPHORESIS
This involves combination of principles of electrophoresis.
First proteins are separated on to the electrophoresis paper, then
the antibodies are allowed to diffuse through the paper and react
with separated protein molecules in the bands.
Its basically for analysis of antigens and antibodies.

15. CAPILLARY ELECTROPHORESIS;
• Capillary of narrow bore tube is employed to separate the samples based on
their size, charge ratio.
• It separate both charge and non-charge molecules.

16. PRINCIPLES OF ELECTROPHORESIS

17. Con’t
Electro-kinetic phenomenon
Its based on coulombs force
• E = F/q where; E = Electric field
• F = coulomb force
• q = change of particles.
• F = E x q , This is the force experienced by
moving particles or molecules in fluid during
electrophoresis. It’s due to electric field.
•

18. Con’t
• Drag force (Fd); This is a force due to friction,
• Fd = f x V. where; f =
frictional coefficient
• V = velocity
• Force due to electric field; F = E x q

19. Con’t
• Force due to electric field; F = E x q
• Force due to friction; Fd = f x v
• In order to allow net movement of the molecules
or particles, F = Fd ( F + Fd = 0)
• Since F = Fd, then q x E = f x V
•
• q/f = V/E = u (Electrophoresis mobility)
•
• V = (q x E)/f , (Velocity of the ions).

20. THE PROCESS OF ELECTROPHORESIS
These molecules often have a positive or a negative charge,
which causes them to respond to an electric current.
Molecules with a positive charge migrate toward the field's
negative pole, and molecules with a negative charge migrate
toward the positive pole.
Molecules with a greater charge tend to move more quickly and
travel farther while the charge is applied.
However, they'll also be slowed by friction, which in turn is
affected both by the size and shape of the molecule and by the
medium used for the test.

21. Con’t
By controlling the electrical current and the friction provided by
the test medium (gel), Researchers can create conditions that
separate biomolecules efficiently.
They can therefore be isolated and studied.
It also permits researchers to identify the differences between
molecules by observing how much they're influenced by the
current.

22. Factors that affects Electrophoresis
i. Nature of charge: The higher the charge, greater is the
electrophoresis mobility.
ii. Size: Bigger molecules have a small electrophoretic mobility
compared to the smaller particles.
iii. Shape: Rounded molecules elicit lesser frictional and
electrostatic retardation compared to sharp ones, therefore
globular proteins move faster than fibrous ones.
iv. Voltage: When voltage in increased, current flow increases
hence electrophoretic separation is accelerated.

23. Con’t
v. Frictional force: This force retards the
movement of the charged molecule.
vi. Electrophoretic mobility: When a p.d. is
applied, the molecule with different overall charges
will begin to separate owing to their different
electrophoretic mobility.
vii. Heat: Heating leads to an increase in rate of
diffusion of samples, formation of convection
current which leads to mixing of separated samples
and thermal instability of samples.

24. APPLICATION
DNAAnalysis: One leading use of electrophoresis is in the
identification and study of DNA and DNA fragments.
Everything from forensics for determining the identity of
individuals that may have been involved in a crime, by linking
their DNA pattern, their electrophoresis pattern, to one that's in a
database.
Antibiotic testing: Electrophoresis is used to separate the
antibodies in the antibiotic from any impurities. This process also
enables researchers to determine the concentration of the
antibiotic, making dosage more accurate.

25. Con’t
Vaccine testing: it is used to test the purity and
concentration of vaccines.
Analysis of proteins and antibodies: it allows research to
study the interactions between proteins and antibodies.
Electrophoresishas facilitated substantial developments in
the study of genetics.
At its core, electrophoresis is about improving and, in many
cases, saving lives.

26. REFERENCES
• Skoog and West, 1963. Fundamental of Analytical
chemistry (2nd ed). Holt Rinehart and Winston, Inc:
London
• Skoog, West, Holler and Crouch (2004). Fundamentals
of Analytical Chemistry. 8th edition, Thomson, London.
• Gary D. Christian (1994). Analytical Chemistry. John
Wiley and Sons Inc., New York
• Jeffery G.H., Bassett J., Denney R.C, and Mendham J
(1989). Vogel’s Textbook of quantitative chemical
analysis. 5th Edition. Longman, London Belcher &
Nutten (1970). Quantitative Inorganic Analysis 3rd
Edition. Butter Worths, London