1 research outputs found
Highly Stable and Sensitive Nucleic Acid Amplification and Cell-Phone-Based Readout
Key
challenges with point-of-care (POC) nucleic acid tests include
achieving a low-cost, portable form factor, and stable readout, while
also retaining the same robust standards of benchtop lab-based tests.
We addressed two crucial aspects of this problem, identifying a chemical
additive, hydroxynaphthol blue, that both stabilizes and significantly
enhances intercalator-based fluorescence readout of nucleic acid concentration,
and developing a cost-effective fiber-optic bundle-based fluorescence
microplate reader integrated onto a mobile phone. Using loop-mediated
isothermal amplification on lambda DNA we achieve a 69-fold increase
in signal above background, 20-fold higher than the gold standard,
yielding an overall limit of detection of 25 copies/μL within
an hour using our mobile-phone-based platform. Critical for a point-of-care
system, we achieve a >60% increase in fluorescence stability as
a
function of temperature and time, obviating the need for manual baseline
correction or secondary calibration dyes. This field-portable and
cost-effective mobile-phone-based nucleic acid amplification and readout
platform is broadly applicable to other real-time nucleic acid amplification
tests by similarly modulating intercalating dye performance and is
compatible with any fluorescence-based assay that can be run in a
96-well microplate format, making it especially valuable for POC and
resource-limited settings