In accordance with this invention, a system, method, and computer-readable medium that selectively scans files stored on a computing device for malware is provided. The capacitor pin and the voltage output pin are for a flying capacitor to be connected therebetween, and thus the switching circuit and the flying capacitor establish a charge pump to convert an input voltage received by the voltage input pin into an output voltage at the voltage output pin. The first barrier area borders on the collector area and has a second conductivity type. The operation corresponding to an object selected by a user is performed by controlling interworking of the shared resources according to the configured topology. The improvement involves maintaining the concentration of urea in the test sample above the threshold value which value is the concentration of urea at which increases in the urea concentration do not affect the accuracy of the assay such as by interfering with the binding between the analyte and the labeled antibody.