A Guide to Choosing the Right Gel for Protein Gel Electrophoresis

May 31, 2024

Protein gel electrophoresis is a fundamental technique in biochemistry, molecular biology, and related fields to separate and analyse proteins. Central to the success of this technique is selecting the appropriate gel matrix. The right gel will have a significant impact on the resolution, sensitivity, and accuracy of protein separation. In this blog post, we’ll explore the two most prominent gels and their use cases.

What is a protein gel?

A protein gel is a common laboratory tool used for separating and analysing proteins based on their size, charge, and other properties. Protein gels come in various forms, including denaturing gels, native gels, and gradient gels, each designed for specific applications:

  1. Denaturing Gels: Denaturing gels contain denaturing agents such as sodium dodecyl sulfate (SDS). This disrupts protein structure and unfolds proteins into linear chains. Denaturing gels are commonly used for SDS-PAGE, where they separate proteins based on their molecular weight.
  2. Native Gels: Native gels preserve the native structure and activity of proteins without denaturation. Laboratories use these gels for native PAGE (Polyacrylamide Gel Electrophoresis) to analyse protein complexes, enzyme activity, and protein-protein interactions under native conditions.
  3. Gradient Gels: Gradient gels contain a gradient of acrylamide concentration. This allows for the separation of proteins over a wide range of molecular weights within a single gel run. Gradient gels offer superior resolution and sensitivity compared to standard linear gels with uniform acrylamide concentrations.

During protein gel electrophoresis, proteins are loaded into wells at one end of the gel and subjected to an electric field, causing them to migrate through the gel matrix towards the opposite end. The rate of protein migration is determined by their size, charge, and the pore size of the gel matrix. After electrophoresis, you can visualise proteins using staining methods such as Coomassie Brilliant Blue, silver staining, fluorescent labelling or transferred to a membrane for antibodies probing for specific target proteins, enabling researchers to analyse protein composition, purity, and molecular weight distribution.

Protein gels are indispensable tools in molecular biology, biochemistry, and biotechnology laboratories. They provide a means to separate, quantify, and analyse proteins for various research and diagnostic applications.

Choosing the Right Protein Gel

The choice of the appropriate chemistry depends on the size, quantity and application of the protein you are separating. Tris-Glycine gels and Bis-Tris Gels are two common types of polyacrylamide gels used for protein electrophoresis in molecular biology laboratories.

Bis-Tris Gels

Bis-Tris gels utilise a buffer system containing Bis-Tris propane, which maintains a neutral pH environment during electrophoresis. These gels offer a wide molecular weight resolving range, from 15 kDa to 10,000 kDa, and better preserve the native state of protein complexes due to their neutral-pH separation. They provide high performance with higher resolution than Tris-Glycine gels, making them suitable for complex protein samples and high-resolution applications.

Tris-Glycine Gels

Tris-Glycine gels are formulated with a buffer system containing Tris base and glycine, typically operating under alkaline conditions. These gels are best for routine protein analysis across a broad size range, from small peptides to large protein complexes. Tris-Glycine gels offer convenience and ease of use, making them ideal for laboratories with high sample throughput or limited resources. While they may not provide the same level of resolution as Bis-Tris gels, they are cost-effective and suitable for routine protein electrophoresis experiments.

In summary, biotech professionals prefer Bis-Tris gels for high-resolution applications requiring sensitive detection methods and minimised protein aggregation. Tris-Glycine gels are suitable for routine protein analysis across a broad size range with convenience and ease of use. You can choose the gel type that best fits your research needs by considering your specific experimental requirements and objectives.

Get Your Protein Gels at Bio Basic Asia Pacific

At Bio Basic Asia Pacific, we provide a range of products essential for protein electrophoresis including both Tris-Glycine and Bis-Tris Gels in both linear and gradient variations. Along with protein ladders, ready-to-use reagents and acrylamide, Bio Basic Asia Pacific is the one-stop solution for all your research needs. Check out the full range of products on our website.