One of the specific tests that a plant diagnostic laboratory might perform is an ELISA or serological test where the plant sap is tested against virus specific antiserum made to the capsid protein of the virus. A PCR test can also be run using the RNA of the virus. A part of the viral genome can be copied and sequenced and then compared to sequences of other potyviruses in the GenBank. If the sequence of the segment matches to a known sequence at 90% or greater it can be assumed the virus in the plant is that same virus.