Process for the purification of nucleic acids

• US 6,235,892 B1
• Filed: 12/21/1999
• Issued: 05/22/2001
• Est. Priority Date: 01/04/1999
• Status: Expired due to Term

• Current Assignee: Sartorius Stedim Biotech GmbH (Sartorius AG)
• Original Assignee: Sartorius AG
• Inventors: Demmer, Wolfgang, Nussbaumer, Dietmar
• Primary Examiner(s): Geist, Gary
• Assistant Examiner(s): CRANE, LAWRENCE E
• Application Number:
  US09/468,706
• Time in Patent Office: 518 Days
• Field of Search: 536/25.4, 536/25.41, 536/25.42
• US Class Current: 536/25.4
• CPC Class Codes: C12N 15/1017 by filtration, e.g. using filters, frits, membranes

Abstract

There is disclosed a membrane process for the purification of nucleic acids in aqueous solutions whereby a lasting reduction of endotoxin content is achieved. The process is suitable for small or large volumes and can be carried out quickly and with simple apparatus.

Claims

1. A process for the purification of nucleic acids comprising the following steps:

(a) directing an aqueous feed solution consisting essentially of a buffered solution containing at least one nucleic acid and at least one endotoxin through at least one microporous weakly basic anion exchange membrane so as to bind at least a portion of both said nucleic acid and said endotoxin to said membrane; and

(b) directing an elution solution consisting essentially of a buffered neutral salt solution of 2M NaCl at pH 5.5 through said membrane so as to selectively elute from said membrane at least a major portion of said nucleic acid bound to said membrane in step (a)

wherein the buffer used in steps (a) and (b) comprises an aqueous solution of tris-HCl and EDTA at pH 8.0 wherein the concentration ratio of tris-HCl to EDTA is 10 to 1.

2. The process of claim 1 further comprising passing said buffer through said at least one membrane between steps (a) and (b) so as to flush non-bonded and non-absorbed contamination from said membrane.

3. The process of claim 1 or 2 wherein said membrane contains a weakly basic anion exchange group selected from the group consisting of primary, secondary and tertiary amino groups.