Luckau Protocols:Low TE
From OpenWetWare
Purpose
Low TE buffer is used to store DNA.
- EDTA chelates Mg2+ and other divalent metals ions (inhibits DNAse and RNAse tp suppress DNA and RNA degradation)
- Tris is a buffering agent to keep the solution at a defined pH
Protocol
1x Low TE = 10 mM Tris-HCl + 0.1 mM EDTA
Volume | Reagent | [Final] |
---|---|---|
20 ml | 0.5M Tris-HCl, pH 8.0 | 10 mM |
0.2 ml | 0.5M EDTA, pH 8.0 | 0.1 mM |
979.8 ml | ddH2O |
- Sterilize by autoclaving for 20 min at 15 psi (1.05 kg/cm2) on liquid cycle
- Store at 4°C or room temperature
FYI
- Note, downstream reactions (PCR) typically require Mg2+, potentially making the presence of EDTA in the reaction problematic. So, when using DNA or RNA that was suspended in TE, keep track of the amount of EDTA in the mix to make sure there is still enough Mg2+ for subsequent reactions to proceed successfully. Each EDTA molecule chelates one Mg2+ ion.
- Many protocols use TE (10mM Tris-Cl and 1mM EDTA), so note that Low TE is different from TE.
- Some people use TE buffers with different pH's for different applications
- DNA is stored at pH 8 to reduce depurination, which is acid catalyzed
- RNA is stored at a slightly lower pH (7.5) because degradation of RNA is base-catalyzed
- Most downstream reactions will not be influenced by the slightly different pH storage conditions.
Sources
- OpenWetWare's Materials TE page
- Cold Spring Harb Protoc; 2006; doi:10.1101/pdb.rec8018
- 10x and 1x TE at cytographica