Hi all,

I am currently planning to do LPS extractions on E. coli and Shigella flexneri (smooth LPS with O-antigen), using the hot phenol-water method as described previously. The protocol calls for extensive dialysis of the LPS extracted, hence I am just wondering what would be the best molecular cut-off/pore size for dialysis membrane/cassettes to be used. I have read that LPS MW is heterogenous in nature, and that LPS tends to aggregate hence they should be of 50 to 100 kDa, and at its purest form (which I assume wouldnt be for my case) LPS consists of consist of 10-20 kDa macromolecules. Any sort of advice or recommendation would be appreciated. Thanks