Filtration processes, kits and devices for isolating plasmids

A process for isolating plasmid DNA from plasmid-containing cells, comprising the steps of:

• a) washing plasmid-containing cells by filtration with a wash solution to disrupt the cell membrane and degrade RNA;
• b) incubating the resulting washed plasmid-containing cells with a lysis/denaturation solution to lyse the cells and denature DNA;
• c) incubating the product of step b) with a renaturation solution for an appropriate period of time and at an appropriate temperature to yield a renatured mixture containing dissolved plasmid DNA, insoluble linear DNA and cellular debris;
• d) filtering the product of step c) to obtain a filtrate from which insoluble linear DNA and cellular debris have been removed;
• and
• e) obtaining plasmid DNA from the filtrate, wherein:
• the process is performed in a multi-well filtration device;
• and
• prior to step a), plasmid containing cells are grown in wells of a multi-well filter plate.

A high throughput DNA sequencing method, comprising the steps of:

• i) growing plasmid containing cells wherein the plasmids comprise DNA to be sequenced;
• ii) washing plasmid-containing cells by filtration with a wash solution to disrupt the cell membrane and degrade RNA;
• iii) incubating the resulting washed plasmid containing cells with a lysis/denaturation solution to lyse the cells and denature DNA;
• iv) incubating the product of step c) with a renaturation solution for an appropriate period of time and at an appropriate temperature to yield a renatured mixture containing dissolved plasmid DNA, insoluble linear DNA and cellular debris;
• v) filtering the product of step d) to obtain a filtrate from which insoluble linear DNA and cellular debris have been removed;
• vi) obtaining plasmid DNA from the filtrate;
• and
• vii) analyzing a nucleic acid fragment obtained from the plasmid DNA by mass spectrometry to determine the sequence of the fragment of DNA of the plasmid.

A high throughput method, comprising the steps of:

• i) growing plasmid containing cells wherein the plasmids comprise DNA to be sequenced;
• ii) washing plasmid-containing cells by filtration with a wash solution to disrupt the cell membrane and degrade RNA;
• iii) incubating the resulting washed plasmid containing cells with a lysis/denaturation solution to lyse the cells and denature DNA;
• iv) incubating the product of step c) with a renaturation solution for an appropriate period of time and at an appropriate temperature to yield a renatured mixture containing dissolved plasmid DNA, insoluble linear DNA and cellular debris;
• v) filtering the product of step d) to obtain a filtrate from which insoluble linear DNA and cellular debris have been removed;
• vi) obtaining plasmid DNA from the filtrate;
• and
• vii) sequencing the plasmid DNA or a nucleic acid fragment obtained from the plasmid DNA, whereby a plurality of plasmid samples are sequenced.