# US 5,707,850 A · Concentration and size-fractionation of nucleic acids and viruses in porous media

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- Number: US 5,707,850 A
- Document ID: US5707850A
- Status: Granted
- Kind: A
- Application number: 08/555,443
- Filed: 1995-11-09
- Granted: 1998-01-13
- Earliest claimed: 1995-11-09
- Inventors: Kenneth D. Cole
- Web page: https://patentgrep.com/patent/US5707850A

## CPC

- C12N 7/00: Viruses; Bacteriophages; Compositions thereof; Preparation or purification thereof (preparing medicinal viral antigen or antibody compositions, e.g. virus vaccines, A61K39/00)
- C12N 15/1003: {Extracting or separating nucleic acids from biological samples, e.g. pure separation or isolation methods; Conditions, buffers or apparatuses therefor}
- C12N 2795/14151: Methods of production or purification of viral material
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)

## Abstract

The present invention relates generally to separation methods, and more particularly to a method to separate nucleic acids and viruses from other substances using porous media by combining flow rate and with electrical field strength. For example, methods to concentrate and size-fractionate of nucleic acids are hereby provided.

## Claims

### Claim 1

A method for separating nucleic acid material from a solution containing nucleic acid material comprising the steps of:
flowing a mixture comprising a buffer medium and a solution containing nucleic acid material through a chromatography media comprising porous beads, the nucleic acid material comprising a material selected from the group consisting of nucleic acids and viruses;
applying an electrical field to the mixture flowing through the chromatography media to retain a retained material on the chromatography media, the retained material consisting essentially of the nucleic acid material; and
recovering the nucleic acid material from the chromatography media.

### Claim 2 (depends on 1)

The method of claim 1, further comprising the step of lowering the pH of the mixture to prevent proteins contained in the mixture from being retained on the chromatography media when the electrical field is applied.

### Claim 3 (depends on 1)

The method of claim 1, wherein the field strength of the applied electric field is from about 0.1 to 50 V/cm.

### Claim 4 (depends on 1)

The method of claim 1, wherein the flow rate of mixture through the chromatography media is from about 0.1 to 200 cm/hr.

### Claim 5 (depends on 4)

The method of claim 4, wherein the field strength of the applied electric field is from about 0.1 to 50 V/cm.

### Claim 6 (depends on 1)

The method of claim 1, wherein the electric field is negative.

### Claim 7 (depends on 1)

The method of claim 1, wherein the recovered nucleic acid material comprises at least one nucleic acid.

### Claim 8 (depends on 1)

The method of claim 1, wherein the recovered nucleic acid material comprises at least one virus.

### Claim 9 (depends on 8)

The method of claim 8, wherein the at least one virus comprises a M13 virus.

### Claim 10 (depends on 1)

The method of claim 1, wherein the solution containing the nucleic acid material comprises in addition to the nucleic acid material at least one substance selected from the group consisting of proteins, carbohydrates and lipids.

### Claim 11 (depends on 1)

The method of claim 1, wherein the solution containing the nucleic acid material comprises proteins in addition to the nucleic material.

### Claim 12 (depends on 1)

The method of claim 1, further comprising the step of increasing the flow rate of the mixture through the chromatography media to increase a minimum size of the nucleic acid material retained on said chromatography media.

### Claim 13 (depends on 1)

The method of claim 1, further comprising the step of decreasing the flow rate of the mixture through the chromatography media to decrease a minimum size of the nucleic acid material retained on said chromatography media.

### Claim 14 (depends on 1)

The method of claim 1, wherein said flowing step comprises pulsing the mixture through the chromatography media.

### Claim 15 (depends on 1)

The method of claim 1, wherein the recovered nucleic acid material comprises DNA.

### Claim 16 (depends on 15)

The method of claim 15, wherein the DNA is selected from the group consisting of: double stranded DNA, single stranded DNA, linear DNA, circular DNA, supercoiled DNA and relaxed (closed circular) DNA.

### Claim 17 (depends on 1)

The method of claim 1, wherein the chromatography media comprises a Sephadex column.