Patent ID: 7695678
Filing Date: 2010-04-13
Classification: B01D,B01J,C12N,C12Q

Abstract:
1. A bifunctional material containing an amino group and a carboxyl group positively charged at a first pH to allow binding of a nucleic acid to the bifunctional material, wherein the charge on the bifunctional material changes from positive to negative with an increase in pH to allow discharging of the bound nucleic acid at a second pH which is higher than the first pH, wherein the bifunctional material is represented by the following Formula 1 or Formula 2: where n is an integer from 1 to 10; and A is from 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, or 2,3,3′,4′-biphenyltetracarboxylic dianhydride; from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, or 2,3,3′,4′-benzophenonetetracarboxylic dianhydride; or a combination, from bis(3,4-dicarboxyphenyl)ether dianhydride; or a combination, generated from bis(3,4-dicarboxyphenyl)sulfone dianhydride; from 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, or 2,3,6,7-naphthalenetetracarboxylic dianhydride, wherein the naphthalene is further unsubstituted or a carbonyl group and a carboxyl group is substituted on any carbon position except for a linking portion of the rings; or a combination, from 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride; from cyclobutanetetracarboxylic dianhydride; from methylcyclobutanetetracarboxylic dianhydride; and from 1,2,3,4-tetracarboxybutane dianhydride; wherein moiety A is a group generated from a reaction between the corresponding tetracarboxylic dianhydride, and an amino group of an NH 2 (CH 2 ) n NH 2 where n is an integer from 1 to 10; and where R