Immobilization of DNA hydrogel plugs in microfluidic channels.

Acrylamide-modified DNA probes are immobilized in polycarbonate microfluidic channels via photopolymerization in a polyacrylamide matrix. The resulting polymeric, hydrogel plugs are porous under electrophoretic conditions and hybridize with fluorescently tagged complementary DNA. The double-stranded DNA can be chemically denatured, and the chip may be reused with a new analytical sample. Conditions for photopolymerization, hybridization, and denaturation are discussed. We also demonstrate the photopolymerization of plugs containing different DNA probe sequences in one microfluidic channel, thereby enabling the selective detection of multiple DNA targets in one electrophoretic pathway.