An on-chip RT-PCR microfluidic device, that integrates mRNA extraction, cDNA synthesis, and gene amplification

Abstract

This paper presents an on-chip integrated reverse transcriptase polymerase chain reaction (RT-PCR) microchip, which integrates the genetic functionalities of messenger ribonucleic acid (mRNA) extraction, complementary deoxyribonucleic acid (cDNA) synthesis, and gene amplification. The proposed RT-PCR microchip consists of a RNA microchannel for extracting mRNA from lysate biological samples, and a DNA microchamber for synthesizing cDNA and amplifying the target gene. As magnetic oligo-dT beads are passed through the RNA microchannel, mRNA bound to the beads was extracted within 1 min by a ferromagnetic wire array inlaid in the RNA microchannel. In the DNA microchamber, the extracted bound mRNA was used for direct synthesis of cDNA followed by amplification of the target gene. To evaluate the performance of the RT-PCR microchip, RT-PCR analyses were performed using various volumes of blood and numbers of breast cancer cells. Additionally, to verify the feasibility of the RT-PCR microchip for clinical applications, it was used for detection of virus-specific genes from specimens of patients infected with respiratory viruses. The continuous and integrated mRNA extraction, cDNA synthesis, and gene amplification process enabled by the proposed RT-PCR microchip suggests its use for high-precision genetic assays with small sample quantities.