[amit (OP)]

CAN SOMEBODY ANSWER ABOUT WHY BORIC ACID USED FOR TBE BUFFER, WHAT IS THE ACTUAL ROLE? ONE CLUE I CAN FIND THAT IT HAS HIGHER BUFFER CAPACITY THAN TAE IS IT CORRECT OR SOME OTHER REASON/

[chris]

Hi Amit, the reason that Tris-borate-EDTA (TBE) buffer is more often used for agarose gel electrophoresis is that it is good for separating smaller DNA fragments (MW < 1000), such as the smaller products of restriction enzyme digests.

TBE also has a greater buffering capacity and will give sharper resolution than TAE buffer. TBE is generally more expensive than TAE, and it also inhibits DNA ligase, which can cause problems if subsequently intend to purify out one of the electrophoresed DNA bands and clone from it.

Chris