Convective polymerase chain reaction around micro immersion heater

Polymerase chain reaction (PCR) is performed in the thermal convection created by a micro immersion heater. Instead of repetitive heating and cooling, the temperature gradient induces thermal convection which drives the reaction liquid between hot and cold parts of the chamber. The convection triggers DNA amplification as the DNA melts into two single strands in the hot region and replicates with the use of proteins into twice the amount in the cold region. The constant heater is simply dipped into the reaction solution. Compared to previous experiments, we demonstrate that convective PCR is possible in a robotically accessible open vessel. Our approach compares well with fast PCR cyclers and replicates DNA 500 000 fold within 20 minutes. We reduce the necessary components for PCR to cheap, single-use components and therefore increasing the prospects of bringing PCR to point of care applications-even in third world countries. (C) 2005 American Institute of Physics.