TE buffer

TE buffer is a commonly used buffer solution in molecular biology, especially in procedures involving DNA or RNA. It is called "TE" buffer because it contains Tris, a common pH buffer, and EDTA, a molecule chelating cations like Mg2+. The purpose of TE buffer is to protect DNA or RNA from degradation.

Recipe
A typical recipe for making TE buffer is:


 * 10 mM Tris, bring to pH 7.5 with HCl
 * 1 mM EDTA

Based on nuclease studies from the 80's, the pH is usually adjusted to 7.5 for RNA and 8.0 for DNA. The respective DNA and RNA nucleases are supposed to be less active at these pH values. But pH 8.0 can safely be used for storage of both DNA and RNA.

EDTA further inactivates nucleases, by binding to metal ions required by these enzymes.