Article,
Evaluation of Microfluidic Biosensor Development Using Microscopic Analysis of Molecular Beacon Hybridization Kinetics
(2005)
Abstract
Molecular beacons, oligonucleotide probes that fluoresce upon hybridization
to a target nucleic acid, can be used in microfluidic devices to
detect and quantify nucleic acids in solution as well as inside bacterial
cells. Three essential steps towards the development of such devices
as integrated microfluidic biosensors using molecular beacons were
investigated in the present study. First, experiments using real-time
confocal microscopy indicated that diffusion of DNA molecular beacons
across a 100-µm diameter microfluidic channel took less than one
minute after the flow of reagents was stopped. Second, experiments
to evaluate hybridization kinetics of DNA molecular beacons with
target nucleic acids in solution showed that DNA molecular beacons
can be used to characterize hybridization kinetics in real time in
microfluidic channels and that hybridization signals approached their
maximum in approximately three minutes. Finally, it was demonstrated
that peptide nucleic acid molecular beacons can be used to detect
bacterial cells in microfluidic devices. These results suggest that
the use of microfluidic devices to detect nucleic acids in solution
and in bacterial cells is promising and that further development
of an integrated microfluidic biosensor for bacterial detection based
on this concept is warranted.
