REAL-TIME MONITORING OF DNA-POLYMERASE REACTIONS BY A MICRO ISFET PH SENSOR

Real-time monitoring of enzymatic DNA (or RNA) polymerization reactions is required in the various fields of biotechnology, especially in diagnostic tests based on DNA polymerization and in evolutionary molecular engineering.1,2In the latter field, one of the key processes is a selection of rapidly growing DNA (or RNA) clones, and the real-time monitoring has been realized through optical methods including fluorescence intensity measurement from a dye molecule bound to the polynucleotide.3However, influences of the dye molecule on the reaction cannot be eliminated and the extension of the optical method to large-scale parallel monitoring will be difficult. Other characteristics required for the monitoring devices are as follows: a small size to correspond with the small amount of sample solutions, a fast response time, durability, and thermal resistance (for polymerase chain reaction (PCR)). Here we report on an electrochemical method using a miniaturized pH sensor made of ion-sensitive field effect transistors (ISFETs), which will satisfy almost all these characteristics. © 1992, American Chemical Society. All rights reserved.