For small DNA fragments (<1,000 bp) when recovery is not necessary, we recommend the use of 1X TBE Buffer.

Gels made with TBE Buffer give sharper bands than gels made with TAE Buffer. TBE results in better resolution for closely spaced DNA bands.

For large DNA fragments (>15,000 bp), 1X TAE Buffer enhances separation of large DNA. Since TAE has a lower buffering capacity, it may be necessary either to recirculate the buffer, or periodically mix the buffer between the anodal and cathodal chambers when electrophoresing for an extended period of time.

The time to buffer depletion can vary with the volts/hour and the size of chamber used. Buffer depth over the gel should be 3 to 5 mm deep. Less buffer, and you risk the chance of the gel drying out. Excessive buffer will decrease the resistance of the circuit between the anode and cathode, which results in a decreased voltage gradient through the gel. This causes inefficient DNA mobility, excessive heating, and band distortion.