This image depicted a Centers for Disease Control and Prevention (CDC) scientist placing samples into a real-time PCR machine, known as a Corbett Research Rotor-Gene 6000 thermocycler, in order to identify the various types of poliovirus contained therein. The data from this analysis is stored in a computer, while the software further analyzes the data before being reviewed by a scientist. The themocycler can vary the temperature, which is important, for PCR requires multiple test rounds at different temperatures. In the instrument, viral RNA is copied into DNA and then the DNA is amplified. Specific probes bind to the DNA, in order to determine what type of polio present. One hundred ten labs around the world can run this assay, and can tell if an isolate contains polio, or not, and if so, what kind.