Optimization of a Signal Enhancement Strategy for the Detection of MicroRNA Using Silicon Photonic Microring Resonator Arrays

Abstract

MicroRNAs (miRNAs) are an important class of non-coding RNA
molecules, regulating gene expression at the transcriptional and
post-transcriptional level. As potent gene regulators, miRNAs
have been linked to developmental processes and establishment
and maintenance of tissue differentiation. As a result, miRNA
expression in tissue and blood samples can be associated with
disease types and stages and be used to fully distinguish tissue
types. These findings, among others, have firmly established the
diagnostic value of miRNAs. Recently, our group has shown the
ability of silicon photonic microring resonators to quantitatively
detect miRNA.This technology is scalable, highly multiplexable
(128 sensors/chip), and inexpensive (<$1/assay). Current nucleic
acid analysis methods have distinct disadvantages when compared
to microring resonators. qRT-PCR is incredibly sensitive
but requires expensive reagents and has limited multiplexing capabilities.
Conversely, microarrays are highly multiplexable, but
labor intensive and expensive. Here we use the microring resonator
platform to quantitate expression levels of 7 miRNAs relevant
to distinguishing tissue type, while also leaving sensors to
normalize data and compare the results to those obtained from
qRT-PCR (the current gold standard).