In a gateway system for connecting a telephone network utilizing a common channel signaling system No. The methods of the invention detect extracellular COX-2 RNA in blood, plasma, serum, and other bodily fluids. The system can include, among other things, a tubular reactor, a rectification column, a condensation assembly, and a conduit network. One end of the first switching capacitor is coupled to the first comparator input terminal, and another end of the first switching capacitor is selectively coupled to one of two different voltages.