Methods for obtaining modified DNA from a biological specimen

1 . A method for obtaining modified DNA from a biological specimen comprising the steps of

1) obtaining a cell suspension from the specimen, if necessary;

2) passing the cell suspension through a first filter under conditions sufficient to obtain filter-bound cells and suspended DNA;

3) lysing the filter-bound cells under conditions sufficient to release cellular DNA;

4) modifying the DNA bound to the filter under conditions sufficient to release the modified DNA from the filter into a flow-through volume;

5) passing the flow-through volume through a second filter under conditions sufficient to capture the modified DNA to the second filter; and

6) eluting the modified DNA from the second filter.

2 . The method of claim 1 wherein the biological specimen is in aqueous form.

3 . The method of claim 2 wherein the biological specimen is selected from the group consisting of serum, whole blood, plasma, urine, cerebral spinal fluid, tears, semen, aqueous humor and intestinal fluid.

4 . The method of claim 2 wherein the biological specimen is selected from the group consisting of gynecologic smears such as Pap smears; sputum samples; brushings such as bronchial, gastric, or esophageal brushing; washing such as bronchial or gastric washings; fluids such as urine, cerebral spinal fluid, pleural fluid, or abdominal fluid; synovial fluid; fine needle aspiration material; tumor touch samples; and seminal fluid.

5 . The method of claim 1 wherein the filter is selected from the group consisting of Zymo ZRC GF Filter, Polyethersulfone (PES), Mixed Cellulose Esters (MCE), Nylon, Fiberglass and DNA-binding filters that are available as a part of DNA Extraction kits.

6 . The method of claim 1 wherein the DNA modification is selected from the group consisting of methylation, bisulfite modification, biotinylation, restriction endonuclease digestion, fragmentation, fluorescein labeling, sulfurization and phosphorylation.