Hi Willy,

I am unclear what you are specifically asking.

For my typical large scale E.coli expression - for a cell mass of 2.5 - 2.7 grams; I use 15 mL of lysis buffer which contains Tris pH 8.0, 1 mg/mL lysozyme and 1X protease inhibitor cocktail.

For sonication, you need to find a setting that you lyse the e.coli but not too strong that will break your protein. I hope that answers your question.

Hi Willy

Ratios of wet cell weight to buffer range from 1:1 to 1:4 grams/mL.

Hope this helps