THERMAL CYCLING DESIGN ALTERNATIVES FOR THE POLYMERASE CHAIN REACTION

Abstract

PCR (polymerase chain reaction) is a process by which a small amount of DNA is amplified many times to yield an easily detectable amount. This process is widely used for the detection of bacterial pathogens for biodefense, in basic research, criminal identification, and disease detection in humans. The reaction mixture must be cycled repeatedly between three different temperature levels in PCR. The reaction mixture is first heated at 94 °C, cooled to 54 °C, and then heated to 72 °C. This cycle is repeated 20-40 times. The main objective of the work reported here is to evaluate alternative heating/cooling schemes for PCR with the ultimate goal of speeding up a PCR reaction. A secondary goal is to arrive at a design that is consistent with battery operation to allow for a portable PCR device. Insight is gained about interactions between the PCR reaction and the engineering system.