Electrophoresis

Question 1

What is protein electrophoresis

Answer 1

Question 2

What factors affect rate of migration in eectrophoresis

Answer 2

Question 3

What are the 4 types of protein electrophoresis

Answer 3

Question 4

What are the properties of acrylamide gel

Answer 4

Question 5

What is denaturing gel electrophoresis (SDS PAGE) (1st type of electrophoresis)

Answer 5

Question 6

What is the role of SDS

Answer 6

Question 7

What are discontinuous gels

Answer 7

Question 8

What is the role of glycine in discontinuous gels

Answer 8

Question 9

How does concentrating proteins in the stacking gel in discontinuous gels work

Answer 9

Migration a polyacrylamide gel using an electric field.
Denaturing PAGE, stacking gel pH close the Gly pKa,
Species migrate as Cl->Protein> Gly which creates a
conductivity gradient and therefore a voltage gradient across three mobile species. Subsequently the species at the rear of the mobile region experience high voltage and therefore speed up and concentration occurs
during migration through the stacking gel.

Question 10

What is native gel PAGE

Answer 10

Question 11

What is isoelectric focussing

Answer 11

Question 12

What is 2D page and how does it work

Answer 12

Question 13

What are the advantages of capillary electrophoresis

Answer 13

Question 14

What are the disadvantages of capillary electrophoresis

Answer 14

Question 15

What are the requirements of capillary electrophoresis

Answer 15

Question 16

What is capillary electrophoresis *

Answer 16

Capillary electrophoresis (CE) is an analytical technique used to separate ionic species based on their charge and size. It operates by applying an electric field across a narrow capillary tube filled with an electrolyte solution. Molecules in the sample migrate through the capillary at different rates depending on their charge, size, and the viscosity of the medium

In CE, positively charged species move toward the negatively charged electrode (cathode), while negatively charged species move toward the positively charged electrode (anode). Neutral molecules may move along with the electrolyte flow but do not experience separation due to the electric field

Question 17

What is electro osmosis*

Answer 17

Electroosmosis (or electro-osmotic flow) refers to the movement of liquid through a porous material or a capillary tube when an electric field is applied. This occurs because, in an electrolyte solution, the walls of the capillary or pores typically acquire a surface charge. This creates a layer of counter-ions (ions of opposite charge) near the walls, called the electric double layer.

When an electric field is applied, these counter-ions move in the direction of the electric field. As they move, they drag the surrounding solvent molecules with them, causing the entire liquid to flow. This phenomenon is crucial in techniques like capillary electrophoresis, where electroosmotic flow helps drive the overall movement of the sample through the capillary, aiding in the separation of components.

Question 18

What is capillary isoelectric focusing*

Answer 18

separates molecules, typically proteins or peptides, based on their isoelectric points

In CIEF, the capillary is filled with a solution containing a pH gradient, usually created by a mixture of ampholytes, which are small molecules with varying pI values. When an electric field is applied, charged molecules move within the pH gradient toward the region where the surrounding pH equals their isoelectric point. Once they reach this point, the molecules stop migrating, since they no longer carry a net charge.