This document describes a method for detecting viruses in potatoes using tuber grafting. The objective is to detect virus in potato tubers. It explains that viruses can pass from infected to healthy potato tubers if their tissues are joined. The method involves taking cores from virus-containing and healthy potato tubers and grafting them together, then growing the grafted tuber to see if symptoms develop, indicating the presence of a virus. The healthy and infected potato tissues serve as controls. If symptoms appear on the grafted tuber after 3-4 weeks, it indicates the healthy tuber was infected by the virus from the other tissue.