A PCR control system to overcome challenging conditions. By directly monitoring the hybridization of fluorescently labelled L-DNA mimics of the template DNA strands and primers, it is possible to improve the efficiency of PCR in challenging conditions. This approach eliminates some of the sample preparation and trial and error that would otherwise be required for difficult sample types such as urine or other samples that contain high levels of salts. In addition, this approach enables on-demand PCR in most any environment.