In most traditional PCRs the resulting products are analyzed after the PCR has been completed. This is called end-point analysis and is normally qualitative of nature rather than being quantitative. For this sort of analysis, products are mostly analyzed on an agarose gel and visualized using ethidium bromide as a fluorescent dye. Direct correlation between signal strength and initial sample concentration is not possible using end-point analysis since PCR efficiency decreases as the reaction nears the plateau phase. Real-time PCR, however, offers an accurate and rapid alternative to traditional PCR. Real-time PCR offers the researcher the opportunity to amplify and analyze the product in a single tube using fluorescent dyes. This is known as homogenous PCR. During a real-time PCR the increase in fluorescence is correlated with the increase in product. Through the use of different specific, dyes real-time PCR can be used to distinguish between different strains of a virus and even to detect point mutations. The major advantage of real-time PCR is that analysis of resulting products using gel electrophoresis is not required. This means that realtime PCR can be implemented as a high-throughput technique for sample screening.
Real time PCR has been described for detection and discrimination of PVYO and PVYN isolates and for reliable discrimination between PVYNTN and PVYN isolates.
Read more about this topic: Potato Virus Y, Diagnostic Techniques For Detection of Potato Virus Y