Electrophoresis is a laboratory technique that uses an electric field to separate charged molecules—such as DNA, RNA, or proteins—based on their size, shape, and charge. It is a cornerstone of molecular biology, biochemistry, and forensic science.
🌍 Definition
- Electrophoresis: Movement of charged particles through a medium (often a gel) under the influence of an electric field.
- Principle: Negatively charged molecules migrate toward the positive electrode, while positively charged molecules move toward the negative electrode.
🔑 Types of Electrophoresis
| Type | Medium | Purpose | Example Use |
|---|---|---|---|
| Gel Electrophoresis | Agarose or polyacrylamide gel | Separates DNA, RNA, proteins by size | DNA fingerprinting, protein analysis |
| Capillary Electrophoresis | Narrow capillary tubes | High-resolution separation | DNA sequencing, pharmaceutical analysis |
| Paper Electrophoresis | Filter paper | Early method for amino acids/proteins | Historical biochemical studies |
| Isoelectric Focusing | pH gradient gel | Separates proteins by isoelectric point | Protein characterization |
| 2D Electrophoresis | Combination of methods | Separates proteins by charge and size | Proteomics research |
📚 Applications
- Genetics: DNA profiling, sequencing, and mutation detection.
- Biochemistry: Protein purification, enzyme studies.
- Medicine: Diagnosing diseases (e.g., sickle cell anemia via hemoglobin electrophoresis).
- Forensics: DNA fingerprinting for criminal investigations.
- Archaeology/Anthropology: Analyzing ancient DNA or proteins from remains.
🛠 How It Works (Gel Electrophoresis Example)
- Sample is loaded into wells in a gel.
- Electric current is applied.
- Molecules migrate through the gel matrix.
- Smaller molecules move faster; larger ones move slower.
- Bands are visualized using stains or fluorescent markers.
✨ Summary
Electrophoresis is a powerful separation technique that sorts biomolecules by charge and size, enabling genetic, biochemical, medical, and forensic discoveries.
Sources: Nature Education overview, Khan Academy electrophoresis intro, Britannica electrophoresis entry.
