Methods for preserving DNA integrity

• US 6,551,777 B1
• Filed: 01/24/2000
• Issued: 04/22/2003
• Est. Priority Date: 02/25/1999
• Status: Expired due to Term

• Current Assignee: Exact Sciences Corporation
• Original Assignee: Exact Sciences Corporation
• Inventors: Moore, James K., Huntress, Frederick A. Jr., Shuber, Anthony P.
• Primary Examiner(s): Yucel, Remy
• Assistant Examiner(s): KATCHEVES, KONSTANTINA T
• Application Number:
  US09/491,093
• Time in Patent Office: 1,184 Days
• Field of Search: 435/6, 435/91.1, 435/91.2, 435/810, 436/94, 536/23.3, 536/24.31, 536/24.33, 536/25.3, 536/25.41, 536/25.4, 536/25.42
• US Class Current: 435/6.1
• CPC Class Codes: C12N 15/1003 Extracting or separating nucleic acids from biological samples, e.g. pure separation or isolation methods; Conditions, buffers or apparatuses therefor
• CPC Class Codes: C12Q 1/6806 Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 2527/125 Specific component of sample, medium or buffer

Abstract

Methods for extracting DNA from a biological sample that result in a higher yield of target DNA than conventional methods. More particularly, methods for extracting DNA include exposing the biological sample to inhibitors of DNA degradation.

Claims

1. A method for preserving the integrity of DNA in a stool sample, the method comprising:

exposing the stool sample to EDTA in a range from about 0.250 gram EDTA per gram of stool to about 0.782 gram EDTA per gram of stool to preserve the integrity of DNA.

2. The method of claim 1 further comprising a step of extracting a target DNA.

3. The method of claim 2 wherein the step of extracting comprises a phenol-chloroform extraction.

8. The method of claim 1 comprising exposing the sample to EDTA in a range from about 0.250 gram EDTA per gram of stool to about 0.521 gram EDTA per gram of stool to preserve the integrity of DNA.

9. The method of claim 1 comprising exposing the sample to about 0.391 gram EDTA per gram of stool to preserve the integrity of DNA.

4. A method for preserving the integrity of DNA in a sample containing exfoliated cells, the method comprising:

exposing the sample to EDTA in a range from 0.250 gram EDTA per gram of sample to about 0.782 gram EDTA per gram of sample to preserve the integrity of DNA.

5. The method of claim 4 wherein the sample is obtained from stool.

6. The method of claim 4 further comprising extracting a target DNA.

7. The method of claim 6 wherein the step of extracting comprises a phenol-chloroform extraction.

10. The method of claim 4 comprising exposing the sample to EDTA in a range from about 0.250 gram EDTA per gram of sample to about 0.521 gram EDTA per gram of sample to preserve the integrity of DNA.

11. The method of claim 4 comprising exposing the sample to about 0.391 gram EDTA per gram of sample to preserve the integrity of DNA.