Handling DNA
Storage of DNA
Purified DNA should be stored at –20°C or –70°C under slightly basic conditions (e.g., Tris·Cl, pH 8.0 or TE buffer; see tables 1 M Tris·Cl and TE buffer) because acidic conditions can cause hydrolysis of DNA. Avoid repeated freeze-thawing as this will lead to precipitates.
Diluted solutions of nucleic acids (e.g., dilution series used as standards) should be stored in aliquots (in siliconized tubes, where possible) and thawed once only. This avoids adsorption of nucleic acids to the tube walls, which would reduce the concentration of nucleic acids in solution.
1 M Tris·Cl
| Component | Amount per liter |
|---|---|
| Tris base | 121.1 g |
TE buffer
| Component | Amount per liter |
|---|---|
| 1 M Tris·Cl, pH 7.4 | 10 ml |
| 0.5 M EDTA, pH 8.0 | 2 ml |