|Electrophoresis| Class 11th| Chapter| Cell structure and function |

Electrophoresis Overview Electrophoresis is a technique used in molecular biology to separate molecules based on their size, charge, and shape. It's most commonly used to separate DNA, RNA, and proteins. Here's a brief overview, especially tailored for Class 11 biology students: Principle: Molecules will move in an electric field because they have a charge. The rate at which they move depends on the size, shape, and charge of the molecule, as well as the strength of the electric field and the nature of the gel or medium they're moving through. Agarose Gel Electrophoresis: Purpose: Used mainly for DNA and RNA separation. Procedure: DNA samples are loaded into wells of a gel made from agarose (a substance derived from seaweed). An electric current is applied. DNA fragments will move towards the positive electrode because they are negatively charged. Smaller fragments move faster than larger ones. Polyacrylamide Gel Electrophoresis (PAGE): Purpose: Used for protein and smaller DNA or RNA separation. Procedure: Similar to agarose gel, but the gel is made from polyacrylamide which has smaller pores and can resolve smaller molecules better. SDS-PAGE: SDS-PAGE stands for Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis. It's a type of PAGE where proteins are coated with SDS, a detergent that gives them a negative charge and denatures them, making them linear. This means proteins move based on size, not their native charge. Staining and Visualization: After electrophoresis, the molecules in the gel can be stained to visualize them. Ethidium bromide is used for DNA (it's a fluorescent dye), and proteins might be stained with Coomassie blue or silver stain. Applications: DNA fingerprinting: Used in forensics to compare DNA samples. Disease diagnosis: Identify specific genes or mutations. Research: Studying genes, proteins, and their functions. #biology #electrophoresis