The present invention relates to systems and methods for the real time processing of nucleic acid during polymerase chain reaction (PCR) and thermal melt applications. According to an aspect of the invention, a system for the rapid serial processing of multiple nucleic acid assays is provided. In one embodiment, the system includes, but is not limited to: a microfluidic cartridge having microfluidic (flow-through) channels, a fluorescence imaging system, a temperature measurement and control system; a pressure measurement and control system for applying variable pneumatic pressures to the microfluidic cartridge; a storage device for holding multiple reagents (e.g., a well-plate); a liquid handling system comprising at least one robotic pipettor for aspirating, mixing, and dispensing reagent mixtures to the microfluidic cartridge; systems for data storage, processing, and output; and a system controller to coordinate the various devices and functions.