DNA & Protein Electrophoresis

a vertical gel electrophoresis system

What Is Electrophoresis & How Does it Work?

Electrophoresis is a laboratory technique used to transport charged protein molecules and nucleic acids through a solvent using an electrically-charged field. It is considered a simple, rapid, and sensitive analytical technique.

Numerous biological molecules carry a net charge at any pH level other than their isoelectric point and migrate at a rate in proportion to their charge density.

A molecule’s mobility through an electric field depends on the following:

  • Field strength
  • The net charge on the molecule
  • Size and shape of the molecule
  • Ionic strength
  • Properties of the matrix, such as pore size and viscosity

Different types of matrices are used in electrophoresis, including polyacrylamide and agarose. They are both a type of gel. As gel matrices, polyacrylamide and agarose offer a porous media that essentially behaves as a filter.

While polyacrylamide has a small pore size and is well suited for separating a large number of proteins and smaller nucleic acids, agarose has larger pore sizes, making it ideal for separating larger macromolecules, such as protein complexes and large nucleic acids.

Multiple forms of gel electrophoresis are used to separate nucleic acids and proteins, including polyacrylamide gel electrophoresis (PAGE). This form alone has several varieties, which can provide various information about specific proteins of interest.

For example, denaturing and reducing sodium dodecyl sulfate PAGE (SDS-PAGE) with a discontinuous buffer system is the most widely used electrophoresis technique and separates

proteins primarily by mass. Nondenaturing PAGE, also called native-PAGE, separates proteins according to their mass/charge ratio. Two-dimensional (2D) PAGE separates proteins by native isoelectric point in the first dimension and by mass in the second dimension.

Once a protein or nucleic acid is separated by electrophoresis, it can be detected in the gel matrix using different stains. They are then transferred onto a membrane for detection by western blotting or analyzed using mass spectrometry. For this reason, DNA and protein gel electrophoresis is an essential step in proteomics.

Learn more about Electrophoresis and the consumables powering this technique below.

Electrophoresis Resources

Restriction Enzymes: Overview & Application

Restriction Enzymes: Overview & Application

Restriction Enzymes: Overview Restriction enzymes are a type of nuclease enzyme that recognizes a specific DNA sequence/recognition site and cleaves at or near that specific site. The site recognized …
DNA Markers: Overview & Application

DNA Markers: Overview & Application

DNA Markers: Overview Have you ever thought about how scientists identify the species of an organism? By using DNA markers. DNA markers, also known as genetic markers or molecular markers, are short D…
Coomassie Blue Staining: Definition & Overview

Coomassie Blue Staining: Definition & Overview

Definition: Coomassie Blue Stains Coomassie Brilliant Blue is a family of dyes that are routinely used in labs for protein staining protocols, performed after SDS-PAGE or polyacrylamide gel electropho…
What Is Protein Gel Electrophoresis? Definition & Overview

What Is Protein Gel Electrophoresis? Definition & Overview

Protein gel electrophoresis, or simply protein electrophoresis, is a common technique used in laboratories to separate biomolecules, including DNA, RNA, and proteins, based on size or molecular weight…
What Is a Protein Ladder & How Is It Used During Gel Electrophoresis?

What Is a Protein Ladder & How Is It Used During Gel Electrophoresis?

Protein ladders are used in experiments to estimate the size of proteins of interest and are resolved using gel electrophoresis. They are also known as protein markers, protein standards, or protein m…

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