Patent ID: 7700762

Claim:
A process for the clarification of plasmid DNA comprising the steps of providing a cell lysate stream containing plasmid DNA, subjecting the stream to a first filtration step comprised of a coarse filter formed of a stainless steel sieve having a pore size of from 50 to 200 microns to form a first permeate stream, subjecting the first permeate stream to a second filtration step comprised of a prefilter layer having a pore size of from about 1 to about 2 microns to form a second permeate stream, and subjecting the second permeate stream to a final filtration step comprised of about a 0.22 micron filter to create a third permeate stream and recovering the plasmid DNA from the third permeate stream wherein the recovery is at least 90% of the plasmid present in the cell lysate stream.