EdvoTech Tip: Using Buffer in Electrophoresis Experiments

Agarose gel electrophoresis is a simple yet powerful technique used in the biotechnology laboratory. This biotechnology technique uses electricity and a porous gel matrix to separate mixtures of molecules into discrete zones, or bands, based on the physical properties of the molecule. This includes the molecule’s charge, its shape, and its size. It can be used analyze nucleic acid, proteins, or dyes. Some of the most common questions we receive focus on the electrophoresis buffer. This reagent is included with every Edvotek electrophoresis kit. But what is it, and why is it important for experimental success?

What is Electrophoresis buffer?

  • Electrophoresis buffer is a mixture of buffers and salts. For TAE buffer, this is Tris Buffer pH 8, acetic acid, and EDTA.

How do I dilute electrophoresis buffer?

  • We send buffer to you as a 50x concentrate which you’ll dilute to 1x in your classroom laboratory.  You’ll add one part of concentrate for every 50 of your final solution.  So, if you’re making three liters of buffer, you’d add 60 mL of concentrate. For more guidance, consult our blog post on dilutions!

What does the buffer do in electrophoresis experiments?

  • We use electrophoresis buffer for two main reasons. First, since water is a poor conductor of electricity, we add charged ions to water which allows the current to flow through our gel.  Second, the buffer keeps our samples at a biologically appropriate pH that preserves their charge or structure. 

Want to learn more about the use of electrophoresis buffer? In this EdvoTech Tip Video, we explore the differences between using water and buffer for both DNA and dye electrophoresis experiments.