Design and microfabrication of a molded polycarbonate continuous flow polymerase chain reaction device

The polymerase chain reaction (PCR) is an amplification technique that is used with deoxyribonucleic acid (DNA) and can produce millions of copies of the starting material, even from single molecules. Since its discovery by Kary Mullis in the mid-1980s, PCR has been one of the most important techniques in the arsenal of tools used for genetic analyses. For this research a continuous flow polymerase chain reaction (CFPCR) system was designed, microfabricated from molded polycarbonate, and tested. Finite element modeling was used to model thermal and microfluidic response of the system. X-ray LIGA was used to fabricate mold inserts for the micro fluidic channels. Polycarbonate was used in place of PMMA for the molded device because polycarbonate has a higher glass transition temperature and is better able to withstand the sustained high operating temperature of the continuous flow PCR system. Commercial thin film heaters under PID control were used to supply the necessary heat flux to maintain the steady-state temperatures in the PCR. There are a number of advantages to performing molecular biology on a small scale. The savings in time and money are the most prominent. A reduction of the cost of these experiments is accomplished on a variety of levels. First, this continuous flow microreactor can be mass produced using existing microfabrication techniques (LIGA). The small sample sizes require much smaller volumes of reagents. Many of the enzymes used in molecular biology are quite costly and reducing the volume required per reaction will significantly decrease the cost of the xperiment. By achieving a quicker and less expensive DNA amplification, DNA analysis could become a technique used routinely in clinical medicine, leading to a vast improvement in medical care