AimsSingapore grouper iridovirus (SGIV) is a devastating aquaculture virus responsible for heavy economic losses to grouper, Epinephelus sp. aquaculture. The aim of this study was to develop a rapid and sensitive detection method for SGIV infections in infected groupers. Methods and ResultsWe previously generated DNA aptamers against SGIV-infected cells. In this study, we established and characterized a novel aptamer (Q3)-based enzyme-linked apta-sorbent assay (ELASA) for the detection of SGIV infection in Epinephelus coioides. The Q3-based ELASA could detect SGIV infection rapidly invitro and invivo, with high specificity and stability. Q3-based ELASA specifically recognized SGIV-infected cells, but not other-virus-infected cells or uninfected cells. Q3-based ELASA detected SGIV infection in a dose-dependent manner at Q3 concentrations as low as 125nmol l(-1). The results in relation to SGIV-infected cells (5x10(4)), incubation time (1min) and incubation temperature (37 degrees C) demonstrated that Q3-based ELASA could detect SGIV infection quickly and stably, superior to antibody-based enzyme-linked immunosorbent assay. Q3-based ELASA could detect the presence of SGIV infection in kidney, liver and spleen samples invivo, at dilutions of 1/50, 1/100 and 1/50 respectively. The complete detection process took 1-2h. ConclusionsQ3-based ELASA could be a useful tool for diagnosing SGIV infection. Significance and Impact of the StudyThis is the first developed aptamer-based ELASA for detecting SGIV infection, and is widely applicable in grouper aquaculture industry in light of its rapidity, and high specificity and stability.