[10] Gel Electrophoresis Flashcards
What is Gel Electrophoresis?
A technique used to separate DNA, RNA, or protein molecules based on their size and charge.
What is the principle of Gel Electrophoresis?
Molecules are separated by size and charge under the influence of an electric field.
What is the gel in Gel Electrophoresis?
A matrix that provides a sieving effect, allowing smaller molecules to travel faster.
What are the two common types of gel used in Gel Electrophoresis?
- Agarose
- Polyacrylamide
Define “Agarose Gel”.
A type of gel used in electrophoresis, ideal for separating larger molecules like DNA and RNA.
Define “Polyacrylamide Gel”.
A type of gel used in electrophoresis, better for separating smaller molecules like proteins.
What is the purpose of the buffer in Gel Electrophoresis?
It provides ions that carry a current and maintains the pH of the system.
Why is a loading dye used in Gel Electrophoresis?
To provide color and density to the samples, and to track the progress of the electrophoresis.
Why are DNA samples negatively charged in Gel Electrophoresis?
Because DNA molecules have a phosphate backbone that is negatively charged.
In what direction do DNA samples move in Gel Electrophoresis?
Toward the positive electrode, because DNA is negatively charged.
How is the size of a DNA fragment estimated in Gel Electrophoresis?
By comparing its migration distance to a DNA ladder, a standard reference.
What is a DNA ladder in Gel Electrophoresis?
A mixture of DNA fragments with known sizes used as a reference.
What is the role of Ethidium Bromide in Gel Electrophoresis?
A staining agent that intercalates into DNA and makes it visible under UV light.
Define “Ethidium Bromide”.
A fluorescent dye used to stain DNA in gel electrophoresis.
What safety precautions should be taken when handling Ethidium Bromide?
It’s a mutagen and should be handled with gloves and disposed of properly.
What is the role of an electric field in Gel Electrophoresis?
It drives the movement of the charged molecules through the gel.
How is Gel Electrophoresis used in DNA fingerprinting?
It separates DNA fragments that are then compared for similarities and differences.
How can the results of Gel Electrophoresis be visualized?
Using UV light after staining with a fluorescent dye like Ethidium Bromide.
What is the role of the wells in a gel electrophoresis setup?
They are the starting point where the DNA samples are loaded into the gel.
Why is Gel Electrophoresis important in molecular biology?
It allows for the separation, identification, and analysis of DNA, RNA, and proteins.
Why is DNA negatively charged?
DNA is negatively charged due to the presence of phosphate groups in its backbone, each of which carries a negative charge.
