This standard specifies the use of reverse transcription-polymerase chain reaction method for the determination of tobacco mosaic virus (TMV), potato virus Y (PVY), cucumber mosaic virus (CMV) and tobacco etch in tobacco seeds, seedlings and fresh tobacco leaf samples. virus (TEV). This standard is applicable to the determination of tobacco mosaic virus (TMV), potato virus Y (PVY), cucumber mosaic virus (CMV) and tobacco etch virus (TEV) in tobacco seeds, seedlings and fresh tobacco leaf samples.