A power-efficient thermocycler based on induction heating for DNA amplification by polymerase chain reaction

Abstract

We have built a thermocycler based on the principles of induction heating for polymerase chain reaction (PCR) of target sequences in DNA samples of interest. The cycler has an average heating rate of ~0.8°C/s and a cooling rate of ~0.5°C/s, and typically takes ~4 h to complete a 40-cycle PCR protocol. It is power-efficient (~6 W per reaction tube), micro-processor controlled, and can be adapted for battery operation. Using this instrument, we have successfully amplified a 350 bp segment from a plasmid and SRY, the human sex determining gene, which occurs as a single-copy sequence in genomic DNA of human males. The PCR products from this thermocycler are comparable to those obtained by the use of commercially available machines. Its easy front-end operation, low-power design, portability and low cost makes it suitable for diagnostic field applications of PCR.