Method and apparatus for isolating and purifying nucleic acid using a single surface

1. A bead for isolating nucleic acid from cells, comprising

a material represented by Formula 1 below bound to the surface of the bead:

where Z 1 is a carboxyl group or an amino group;

R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 9 and R 11 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C6-C30 aryloxy group;

R 4 is a substituted or unsubstituted C4-C20 alkyl group, a substituted or unsubstituted C4-C20 alkoxy group, a substituted or unsubstituted C4-C20 alkenyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C6-C30 aryloxy group;

R 10 is a nitrogen-containing heteroaryl or heterocyclic group of 3-30 carbon atoms;

j, k, l and m are each independently an integer in the range of 1-10; and

n is an integer in the range of 1-30,000.

2. The bead of claim 1 , wherein R 10 is a pyridinyl group or an imidazolyl group.

3. The bead of claim 1 , wherein R 1 and R 5 are each a hydroxyl group.

4. A method of making a bead surface for isolating nucleic acid from cells, comprising:

reacting a bead with a compound to introduce a hydrophobic functional group, wherein the hydrophobic functional group is a substituted or unsubstituted C4-C20 alkyl group, a substituted or unsubstituted C4-C20 alkoxy group, a substituted or unsubstituted C4-C20 alkenyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C6-C30 aryloxy group;

reacting the bead with a second compound to introduce a charge switching moiety, wherein the charge switching moiety is a nitrogen-containing heteroaryl or heterocyclic group of 3-30 carbon atoms.