TL;DR: Standard 1X TE buffer contains 10 mM Tris-HCl pH 8.0 and 1 mM EDTA. For 100 mL from common stocks, mix 1 mL 1 M Tris-HCl pH 8.0 with 200 µL 0.5 M EDTA pH 8.0, then add nuclease-free water to 100 mL.
TE buffer is a simple nucleic-acid storage buffer. Tris stabilises pH, while EDTA chelates divalent metal ions such as Mg²⁺ that many nucleases require. That makes TE useful for DNA storage, plasmid preparation, oligonucleotide handling and molecular biology workflows.
1X TE composition
- 10 mM Tris-HCl, pH 8.0
- 1 mM EDTA, pH 8.0
1X TE recipe from stock solutions
| Final volume | 1 M Tris-HCl pH 8.0 | 0.5 M EDTA pH 8.0 | Water |
|---|---|---|---|
| 100 mL | 1 mL | 200 µL | to 100 mL |
| 500 mL | 5 mL | 1 mL | to 500 mL |
| 1 L | 10 mL | 2 mL | to 1 L |
10X TE recipe
10X TE contains 100 mM Tris-HCl and 10 mM EDTA.
| Final volume | 1 M Tris-HCl | 0.5 M EDTA | Water |
|---|---|---|---|
| 100 mL | 10 mL | 2 mL | to 100 mL |
| 500 mL | 50 mL | 10 mL | to 500 mL |
| 1 L | 100 mL | 20 mL | to 1 L |
Why EDTA protects DNA
Many nucleases depend on Mg²⁺ or other divalent ions. EDTA chelation can reduce nuclease activity, which is one reason it is widely used in nucleic-acid buffers. Primary studies have shown EDTA can protect high-molecular-weight DNA under selected storage and extraction conditions.
When TE can cause problems
EDTA can inhibit downstream enzymes that require Mg²⁺, including many polymerases, ligases and nucleases. If a DNA sample will be used directly in a sensitive enzymatic reaction, use a low-EDTA TE formulation or dilute the DNA sufficiently that EDTA is negligible in the reaction.
TE vs water for DNA storage
Water avoids EDTA carryover but provides less protection from nuclease activity and pH drift. For long-term DNA storage, TE is often more forgiving. For short-term PCR setup, nuclease-free water can be more convenient if DNA quality is already secure.
Low-EDTA TE
A common low-EDTA alternative uses 10 mM Tris-HCl with 0.1 mM EDTA. This reduces chelation in downstream reactions while retaining some protection against nuclease activity.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| PCR inhibition | Too much EDTA carried into the reaction | Dilute the DNA, use low-EDTA TE or clean up the sample. |
| DNA degrades | Nuclease contamination or repeated freeze-thaw | Use clean nuclease-free handling and aliquot samples. |
| pH incorrect | Tris stock made at a different temperature | Check pH at room temperature and remake if needed. |
Frequently asked questions
Is TE buffer suitable for RNA?
It can be used, but RNA workflows require strict RNase-free technique. Many RNA applications use dedicated RNase-free buffers tailored to the downstream assay.
Can plasmid DNA be stored in TE?
Yes. TE is widely used for plasmid and genomic DNA storage.