Capillary electrophoresis (CE) is a laboratory technique used to separate and analyze small molecules, such as DNA fragments, RNA, proteins, and ions, based on their charge-to-size ratio. CE uses a narrow glass capillary tube filled with an electrolyte buffer, which is subjected to an electrical field. When the sample is introduced into the capillary, the molecules migrate through the electrolyte buffer based on their charge and size.
The process of capillary electrophoresis involves the following steps:
- Preparation of the capillary: The capillary tube is filled with an electrolyte buffer and the ends of the capillary are inserted into vials containing the buffer.
- Injection of the sample: The sample is introduced into the capillary tube using various techniques, such as electrokinetic injection, pressure injection, or hydrodynamic injection.
- Electrophoresis: An electrical field is applied across the capillary tube, causing the charged molecules in the sample to migrate through the electrolyte buffer towards the opposite electrode.
- Detection: As the molecules migrate through the capillary tube, they are detected by a detector, such as a UV detector or a fluorescence detector, which measures their concentration and retention time.
- Data analysis: The data collected by the detector is analyzed to determine the identity, size, and quantity of the molecules in the sample.
Capillary electrophoresis is a powerful analytical technique that is widely used in various fields, including chemistry, biology, and forensics. It has several advantages over other separation techniques, such as high resolution, high sensitivity, and low sample and reagent consumption. It is a valuable tool for the analysis of complex mixtures of small molecules, providing important insights into biological and chemical processes.