Agrose Gel electrophoresis?

[barathvaj]

Today,I did Agrose gel electrophoresis,and DNA and RNA are loaded as Sample

In that We used TAE Buffer in the electrophoresis tank ,Why It is used?

It is used for conductivity or pH maintanence?

If it is used for pH maintanence,While doing the process how pH changes?

My lecturer told me that DNA should be runned at 7.5-7.8pH,Why?

Thanks for all,Plz clear my doubts!