A microchip for nucleic acid isolation and enrichment

This paper presents a microchip that effectively isolates and enriches target-binding single-stranded DNA (ssDNA) in a randomized DNA mixture using solid-phase extraction (SPE) and electrophoresis. The microchip consists of isolation and enrichment microchambers that are connected by a microchannel partially filled with agarose gel. Single-stranded DNA oligomers in the randomized mixture are captured via specific binding onto human immunoglobulin E (IgE) that is immobilized on microbeads in the isolation chamber. Following elution, the oligomers are separated from impurities via electrophoretic transport through the gel-filled microchannel to the enrichment chamber. Experimental results show that this approach can enhance the sensitivity of ssDNA detection methods in dilute and complex biological samples.