What is the Difference Between Tris Base and Tris HCl?

The main difference between Tris base and Tris HCl lies in their chemical composition and pH characteristics:

1. Tris base: Tris base, also known as tris(hydroxymethyl)aminomethane, has the chemical formula C4H11NO3. It is an organic compound primarily used in molecular biology to make buffer solutions. Tris base is a basic buffer, meaning it is alkaline and helps maintain a stable pH in solutions.
2. Tris HCl: Tris HCl, or tris hydrochloride, has the chemical formula C4H11NO3·HCl. It is a salt formed by the reaction of Tris base with hydrochloric acid (HCl). Tris HCl is an acidic buffer, also used to maintain a stable pH in solutions, but it has a lower pH compared to Tris base.

When choosing between Tris base and Tris HCl for a specific application, the decision depends on the desired pH and the protocol being used. If you need to lower the pH of your buffer, choose Tris HCl. If you need to increase the pH of your buffer, use Tris base. For example, in SDS-PAGE and Western blotting, Tris base is commonly used.

Comparative Table: Tris Base vs Tris HCl

The main difference between Tris Base and Tris HCl is that Tris Base is a basic buffer, while Tris HCl is an acidic buffer. Here is a comparison table highlighting their differences:

Both Tris Base and Tris HCl are used in common buffer recipes such as CTAB DNA extraction buffer, Leammli buffer for SDS-PAGE, TAE buffer, TBE buffer, and TE buffer. The choice between using Tris Base or Tris HCl depends on the specific protocol being used and how you need to adjust the pH of your solution. Tris Base is typically used in electrophoresis buffers, while Tris HCl can be used in preparing Tris buffers for SDS-PAGE and western blotting.