Evaluation of three-dimensional microchannel glass biochips for multiplexed nucleic acid fluorescence hybridization assays

Three-dimensional, flow-through microchannel glass substrates have a potent ial for enhanced performance, including increased sensitivity and dynamic r ange, over traditional planar substrates used in medium-density microarray platforms. This paper presents a methodology for the implementation of mult iplexed nucleic acid hybridization fluorescence assays on microchannel glas s substrates. Fluorescence detection was achieved, in a fist instance, usin g conventional low-magnification microscope objective lenses, as imaging op tics whose depth-of-field characteristics match the thickness of the micro- channel glass chip. The optical properties of microchannel glass were shown , through experimental results and simulations, to be compatible with the q uantitative detection of heterogeneous hybridization events taking place al ong the microchannel sidewalls, with detection limits for oligonucleotide t argets in the low-attomole range.