Local temperature control device using a transparent electrode in the viewing area of a microscope: development and application to RT-PCR
Masahiko Oshige1, 2, Ryo Yokosawa1, Hitomi Shinohara1, Maho Suzuki1, Shinji Katsura1, 2, *
* The author to whom correspondence should be addressed.
1 Department of Environmental Engineering Science, Graduate School of Science and Technology, Gunma University, Japan
2 Gunma University Center for Food Science and Wellness (GUCFW), Japan
Abstract
The reaction temperature plays a key role in observing biochemical reactions through a microscope. In conventional methods, the actual local temperature of the observed area is different from the measured local temperature because the heater and the temperature sensor are far apart. The electrical resistance of indium tin oxide, a transparent electrode, changes with its temperature. Based on this property, we developed a temperature control system for the viewing area of a microscope. In this system, we heated the transparent electrode by Joule heating, and temperature measurement is conducted on the same electrode in a time-sharing manner. Then, we applied this system to temperature cycles for a reverse transcription-polymerase chain reaction in emulsions. Successful DNA amplification was confirmed by observing the fluorescence of FAM, whose quenching was terminated via oligonucleotide cleavage by DNA amplification in the emulsions.Keywords - Indium tin oxide (ITO) electrode, temperature sensor, temperature control, polymerase chain reaction (PCR).