Ct Value

The Ct value, or cycle threshold value, is a measurement used in PCR testing to detect the presence of a virus like COVID-19. It indicates the number of cycles needed to amplify viral genetic material to a detectable level. A lower Ct value means there was more virus present in the sample initially, suggesting a higher viral load. Conversely, a higher Ct value indicates less virus was detected, implying a lower viral load. Ct values help assess how infectious a person might be and inform testing accuracy, but should always be interpreted alongside other clinical information.