WorksheetsElectrophoresis
Total questions: 20
Worksheet time: 10mins
Electrophoresis is best defined as the separation of charged particles based on their
Molecular weight only
Solubility in the solvent
Movement in an electric field
Volatility
In electrophoresis, cations migrate towards the
Cathode
Anode
Neutral electrode
Sample well
Which of the following factors does NOT directly affect electrophoretic mobility?
Charge on the molecule
Size of the molecule
Applied voltage
Colour of the analyte
Electrophoretic mobility (μ) is defined as the ratio of
Charge to mass
Velocity to electric field strength
Distance travelled to time
Voltage to current
Which medium is commonly used in zone electrophoresis?
Agarose or polyacrylamide gel
Distilled water
Organic solvent
Silica column
Paper electrophoresis primarily separates compounds based on differences in
Boiling point
Partition coefficient
Charge and size
Vapour pressure
In polyacrylamide gel electrophoresis (PAGE), separation is mainly influenced by
pH of the buffer
Pore size of the gel
Temperature of the system
Dielectric constant
Which electrophoresis technique is the most suitable for separating proteins based on molecular weight?
Capillary electrophoresis
Paper electrophoresis
Isoelectric electrophoresis
SDS-PAGE
Sodium dodecyl sulfate (SDS) is used in electrophoresis to
Provide uniform negative charge to proteins
Increase buffer capacity
Reduce electrical resistance
Stabilize the gel
Isoelectric focusing separates molecules based on their
Size
Shape
Isoelectric point (pI)
Polarity
At its isoelectric point, a molecule will
Migrate rapidly
Carry maximum charge
Stop migrating
Precipitate immediately
Capillary electrophoresis offers which major advantage?
Requires large sample volume
Low separation efficiency
Poor reproducibility
High resolution and rapid analysis
Which detector is commonly used in capillary electrophoresis?
UV-Visible detector
Flame ionization detector
Thermal conductivity detector
Electron capture detector
The buffer in electrophoresis primarily functions to
Increase sample solubility
Maintain constant pH
Increase conductivity only
Reduce voltage
Which pharmaceutical application commonly uses electrophoresis?
Determination of melting point
Measurement of viscosity
Analysis of amino acids and peptides
Determination of refractive index
Joule heating in electrophoresis is caused by
Sample instability
High ionic strength and voltage
Low buffer concentration
Gel polymerization
Which parameter must be controlled to minimize band broadening in electrophoresis?
Sample colour
Density of sample
Shape of electrodes
Temperature
In pharmaceutical analysis, electrophoresis is especially useful for analyzing
Charged biomolecules
Volatile oils
Non-polar hydrocarbons
Insoluble solids
Compared to chromatography, electrophoresis primarily separates analytes based on
Partitioning between phases
Electrical charge and mobility
Adsorption on stationary phase
Polarity differences
Which of the following is a limitation of electrophoresis?
High separation efficiency
Short analysis time
High sensitivity
Limited to charged species
