Visual Detection of Labeled Oligonucleotides Using Visible-Light-Polymerization-Based Amplification

摘要

DNA biochip technology holds potential for highly parallel,rapid,and sensitive genetic diagnostic screening of target pathogens and disease biomarkers.A primary limitation involves a simultaneous,sequence-specific identification of low copy number target polynucleotides using a clinically appropriate detection methodology that implements only inexpensive detection instrumentation.Here,a rapid(20 min),nonenzymatic method of signal amplification utilizing surface-initiated photopolymerization is presented in glass microarray format.Visible light photoinitiators covalently coupled to streptavidin were used to bind biotin-labeled capture sequences.Amplification was achieved through subsequent contact with a monomer solution and the appropriate light exposure to generate 20-240-nm-thick hydrogel layers exclusively from spots containing the biotin-labeled DNA.An amplification factor of 106 to 107 was observed as well as a detectable response generated from as low as ~10~4 labeled oligonucleotides using minimal instrumentation,such as an optical microscope or CCD camera.