Types of Electrophoresis & Uses

Electrophoresis is a widely used technique in laboratories, primarily for the separation, analysis, and purification of molecules such as DNA, RNA, and proteins. By applying an electric field, this method effectively sorts molecules based on their size, charge, or other physical properties. Its precision and versatility make it an essential tool in fields like molecular biology, biochemistry, and genetics.

Whether you’re analyzing genetic material for research or identifying proteins in a sample, electrophoresis provides valuable insights that help scientists better understand biological processes. This method is integral to innovations in diagnostics, forensic investigations, and drug development, showcasing its importance in both research and practical applications.

In this blog, we’ll explore the basics of electrophoresis, how it works, and its key applications in the laboratory, offering an easy-to-understand yet professional overview for readers of all levels.

What is Electrophoresis?

Electrophoresis is a laboratory method used to separate charged molecules under the influence of an electric field. Molecules like DNA or proteins carry electrical charges, which cause them to migrate through a medium such as a gel when an electric field is applied. The rate of migration depends on factors like the size and charge of the molecules, as well as the properties of the medium. This technique is particularly useful for analyzing and purifying specific components in a mixture, making it a cornerstone of many scientific investigations.

How Does Electrophoresis Work?

The process begins by preparing a gel or liquid medium, typically agarose or polyacrylamide, depending on the type of sample being analyzed. The sample is then loaded into wells at one end of the medium. When an electric current is applied, the charged molecules within the sample move toward the oppositely charged electrode. The movement is based on the charge and size of the molecules: negatively charged molecules move toward the positive electrode (anode), while positively charged molecules move toward the negative electrode (cathode).

As the molecules migrate through the gel, they are separated into bands. By using a marker with known sizes, researchers can compare the mobility of the sample molecules and determine their size or other properties. The gel is then stained to visualize the separated molecules, and the results are analyzed.

Types of Electrophoresis

There are several types of electrophoresis, each designed for specific applications:

Agarose Gel Electrophoresis

Agarose gel electrophoresis is one of the most commonly used techniques in molecular biology, especially for the analysis of nucleic acids (DNA and RNA). Agarose, a polysaccharide derived from seaweed, is used to create a gel matrix through which nucleic acids can migrate.

How It Works: The agarose gel forms a porous structure that allows DNA and RNA molecules to pass through based on their size. When an electric field is applied, smaller molecules travel faster through the gel, while larger molecules experience more resistance and move slower.

Polymerase Chain Reaction 

PCR-based electrophoresis combines the power of polymerase chain reaction (PCR) with electrophoresis to amplify and analyze DNA samples. PCR amplifies specific regions of DNA, which are then separated by size using electrophoresis.

How It Works: PCR amplifies a targeted DNA sequence, and the resulting PCR product is analyzed by gel electrophoresis to confirm its size and integrity. Typically, agarose gel electrophoresis is used for the separation of PCR products.

Capillary Electrophoresis (CE)

Capillary electrophoresis is an advanced technique that separates ions based on their charge and size using a capillary column filled with an electrolyte solution. This method offers high-resolution separation and is often used for small sample volumes and precise analysis.

How It Works: In capillary, a high-voltage electric field is applied to a capillary tube filled with a conductive buffer. Molecules are separated based on their charge-to-size ratio and migrate through the capillary. Detection is typically done by optical methods such as UV absorbance.

 Isoelectric Focusing (IEF)

Isoelectric focusing is a technique that separates proteins or peptides based on their isoelectric point (pI), which is the pH at which a molecule has no net charge. It is often used in combination with other electropop techniques for protein analysis.

How It Works: In IEF, a pH gradient is established in a gel or liquid medium, and when an electric field is applied, proteins migrate to the point where their net charge is zero. This technique allows the separation of proteins based on their unique pI values.

Most Durable Gel Electrophoresis for High Schools

High school laboratories require durable, easy-to-use gel systems that offer consistent results. For educators, the priority is a device that is both reliable and straightforward, making it suitable for beginners. Popular models include the Edvotek M12 Apparatus and the Bio-Rad Mini Sub Cell GT, both of which are built to withstand repeated use while maintaining safety standards. These systems provide an excellent introduction to the principles of gel electrophoresis, preparing students for more advanced applications in higher education.

How Does Electrophoresis Help Save Elephants?

Gel electrophoresis plays a surprising but crucial role in wildlife conservation. By analyzing DNA samples from ivory, scientists can determine the geographic origin of poached elephant tusks. This technique, combined with law enforcement, helps track illegal poaching networks and target conservation efforts more effectively. DNA fingerprinting through has thus become a vital tool in saving endangered elephant populations.

Electrophoresis in Medical Diagnostics

Hemoglobin Electrophoresis (Labcorp)

This test separates and identifies different forms of hemoglobin to diagnose blood disorders such as sickle cell anemia and thalassemia. Labcorp offers reliable hemoglobin electrophoresis services, providing accurate results crucial for patient care.

Urine Protein 

This diagnostic test identifies abnormal proteins in urine, often used to detect kidney disorders and multiple myeloma. By separating proteins based on size and charge, this method provides valuable insights into underlying health conditions.

Conclusion

This is a diverse and powerful technique, with multiple variations tailored to different research and diagnostic needs. From basic applications like agarose gel electrophoresis to advanced methods like capillary electrophoresis and two-dimensional gel electrophoresis, each type provides unique advantages. Understanding the differences between these techniques is crucial for selecting the most appropriate method for your specific research goals, whether you’re analyzing nucleic acids, proteins, or other complex biomolecules.