Devices and methods for plasmid purification

Abstract

The invention provides columns (including pipette tip columns) and automated methods for the purification of nucleic acids including plasmids. Nucleic acids can be purified from unclarified, clarified or partially-clarified cell lysates that contain cell debris. The columns typically include a bed of medium positioned above a bottom frit and with an optional top frit. Plasmid preparation scales include miniprep, midiprep, maxiprep, megaprep and gigaprep.

1 .- 19 . (canceled) 
     
     
         20 . An automated method for large scale plasmid preparation comprising:
 (a) providing a cell lysate, the cell lysate comprising cell debris, liquid, and plasmid DNA;   (b) providing a column, the column configured to capture plasmid DNA;   (c) providing a filter;   (d) passing the cell lysate through the filter to produce a filtrate;   (e) passing the filtrate through the column such that a portion of the plasmid DNA is captured on the column;   (f) passing a wash solution through the column; and   (g) eluting the plasmid DNA by passing a desorption solution through the column, wherein an amount of plasmid DNA eluted from the column is between 20 and 200 μg,   wherein the passing the filtrate through the column, the passing the wash solution through the column, and the eluting the plasmid DNA are performed at predetermined times.   
     
     
         21 . The method of  claim 20 , wherein at least two cell lysates are processed in parallel. 
     
     
         22 . The method of  claim 20 , where in the filter has a pore size greater than 10 μm. 
     
     
         23 . The method of  claim 20 , wherein the filtrate is passed through the column by aspiration/expulsion, vacuum, pressure, or gravity. 
     
     
         24 . The method of  claim 20 , wherein the passing the cell lysate through the filter, the passing the filtrate through the column, and the passing the wash solution through the column are performed by vacuum. 
     
     
         25 . The method of  claim 20 , wherein an area of the filter is at least 3 cm 2 .