Nanodroplet real-time PCR system with laser assisted heating

Abstract

We report the successful application of low-power (~30 mW) laser radiation as an optical heating source for high-speed real-time polymerase chain reaction (PCR) amplification of DNA in nanoliter droplets dispersed in an oil phase. Light provides the heating, temperature measurement, and Taqman real-time readout in nanoliter droplets on a disposable plastic substrate. A selective heating scheme using an infrared laser appears ideal for driving PCR because it heats only the droplet, not the oil or plastic substrate, providing fast heating and completing the 40 cycles of PCR in 370 seconds. No microheaters or microfluidic circuitry were deposited on the substrate, and PCR was performed in one droplet without affecting neighboring droplets. The assay performance was quantitative and its amplification efficiency was comparable to that of a commercial instrument.

TRPV4 channels mediate the infrared laser-evoked response in sensory neurons

“…To estimate the temperature changes of the bath, a fluorescent temperature-sensitive dye (LDS 698; Exciton, Dayton, OH) was used as previously described (Coppeta and Rogers 1998;Kim et al 2009). LDS 698 is active in the range 20 -100°C and was used at a concentration of 10 M. To calibrate the fluorescence intensity changes of the LDS 698 dye on temperature fluxes, the bath without any cells was maintained within a temperature range of 20 -50°C by a heater controller (Harvard Apparatus, Les Ulis, France).…”

Microfluidic Chips for Point‐of‐Care Immunodiagnostics

“…[287][288][289] Lasers can be used to heat precise areas on microfl uidic chips. [290][291][292] An approach used for cooling electronic chips consisting of circulating liquid in microchannels can be used to heat and cool chips using convective heat transfer. [293][294][295] Multiple temperature zones on one chip are easier to implement in fl ow path materials with low thermal conductivity such as polymers instead of materials with high thermal conductivity such as glass or silicon.…”

Toward Integrated Molecular Diagnostic System (<formula formulatype="inline"><tex Notation="TeX">$i$</tex></formula> MDx): Principles and Applications

“…Kim et al . show the successful PCR on chip in nanodroplets dispersed in an oil phase based on the application of low-power ( ~ 30 mW) laser radiation as an optical heating source [58]. For RNA species, the reverse transcription step was additionally incorporated into a single chip for POC clinical diagnostics [59].…”