Buffers for DNA isolation

[snowysummer]

can anyone help me with the following question?

 

i don't understand how come before DNA is isolated, TES buffer is used, but after DNA is isolated, TE buffer is used. The only difference between the two buffers is the presence of 0.15 M NaCl. How come NaCl is required before DNA is isolated?

 

Thanks !!

[CharonY]

There are gazillions of DNA isolation protocols, depending on the organism (sometimes even lab), though most basics are the same.

I could answer more specific if the complete protocol is given.

Do you use TES to resuspend your cells? In that case it could be use to prevent osmolysis. Alternatively there are certain columns to which DNA binds with a high salt-content buffer for instance...

[snowysummer]

thank u for ur reply~ DNA was isolated from salmon testes. TES was added when the testes was ground up into a paste, and centrifuged. after pronase digestion and addition of sds, dna was precipitated in ethanol in the presence of sodium acetate. Then DNA was redissolved in TE buffer.