Mastering Agarose Gel Electrophoresis Techniques and Applications

Agarose gel electrophoresis is a method for separating DNA, RNA, and proteins based on size and charge. The process involves preparing an agarose gel, setting up an electrophoresis tank, and adding ethidium bromide for visualization. DNA samples are loaded into the gel, and an electric current is applied to separate the fragments. The separated DNA is visualized under UV light, allowing for size determination by comparing to a DNA ladder.

What is the primary purpose of agarose gel electrophoresis?

• To synthesize new DNA strands

• To dissolve proteins in a solution

• To separate DNA fragments based on size and charge

• To measure the pH of a solution

Why is it important to heat the agarose solution?

• To sterilize the solution

• To dissolve the agarose powder

• To evaporate excess water

• To increase the pH level

What is the role of ethidium bromide in gel electrophoresis?

• To solidify the gel

• To act as a buffer

• To intercalate between DNA base pairs and fluoresce under UV light

• To increase the speed of DNA migration

What is the purpose of the comb in the electrophoresis tank?

• To mix the agarose solution

• To create wells for loading samples

• To measure the temperature

• To stabilize the gel

Why is a running buffer used in gel electrophoresis?

• To prevent the gel from solidifying

• To increase the gel's transparency

• To provide ions that carry a current and maintain pH

• To dissolve the DNA samples

What is the function of the loading buffer in DNA sample preparation?

• To neutralize the sample's charge

• To solidify the sample

• To dissolve the DNA

• To increase the sample's density and add color

What is a DNA ladder used for in gel electrophoresis?

• To increase the speed of DNA migration

• To act as a control for pH levels

• To serve as a reference for DNA fragment sizes

• To stabilize the gel

How do DNA molecules move through the gel during electrophoresis?

• They remain stationary

• Towards the negative pole due to their positive charge

• Randomly in all directions

• Towards the positive pole due to their negative charge

Why do smaller DNA fragments move faster through the gel?

• They are more soluble in the buffer

• They encounter less resistance

• They are attracted to the negative pole

• They have a higher charge

How are DNA bands visualized after electrophoresis?

• By increasing the electric current

• By heating the gel

• By adding more buffer

• By placing the gel under UV light