Bacterial expressed coat protein : development of a single antiserum for routine detection of Citrus tristeza virus

Abstract

Citrus tristeza virus (CTV) causes one of the most important citrus diseases world-wide and has recently
been detected in Portugal. Early diagnosis based on immunoenzymatic techniques requires significant amounts of
reagents. This research describes the isolation of the coat protein gene of CTV, its expression in Escherichia coli as a
fusion protein containing an N-terminal (His)6 region and its use to raise rabbit polyclonal antibodies. These antibodies
could be used at dilutions higher than 1/80,000 at the detection stage in indirect ELISA tests and were also
efficient for trapping the virus in ELISA and Immunocapture RT-PCR. These characteristics allowed the production
of diagnostic kits based solely on this source of antibodies. A detection spectrum and sensitivity similar to that of a
commercial polyclonal antibody kit was achieved.