CIBA Developed Technology for b - NOVA’ RT-PCR kit for the diagnosis of Viral Nervous Necrosis in finfish          


          Viral Nervous Necrosis (VNN) or Viral Encephalopathy and Retinopathy (VER) is a serious viral disease of finfish caused by Betanodavirus of the family Nodaviridae. The virus is non-enveloped, icosahedral in shape with a diameter of approximately 25 to 30 nm and contains two segments (RNA1 and RNA2) of positive sense single-stranded RNA (ssRNA) with the RNA2 segment containing the sequence for the viral coat protein.  Disease has been reported from more than 35 fish species from tropical to temperate climates from most continents around the world, including India, and most reports of disease have been associated with species in aquaculture facilities. Clinical disease is most commonly observed in larval and juvenile finfish, but adult fish surviving infection can become asymptomatic carriers. Mortality rates of up to 100% are most commonly seen in larval fish and tend to decrease as the size of the infected fish increases. The most common mode of transmission appears to be vertically from sub-clinically infected broodstock to progeny during spawning in hatchery facilities.

 The RT-PCR Kit Technology

           CIBA’s NOVA’ RT-PCR kit is a molecular diagnostic kit developed for early detection of viral nervous necrosis (VNN) caused by betanodavirus in finfish. The kit offers a rapid, specific and sensitive detection system based on the amplification of the coat protein gene of the virus genome segment RNA2. The assay has been validated extensively using field samples from clinically and sub-clinically infected fish from wild and culture facilities across the country. The kit can be used for routine diagnosis of disease, besides as a management tool to screen broodstock, larvae, and even trash fish used as feed in fish hatcheries and selective breeding programme for pathogen free stock development in freshwater, brackishwater and marine ecosystem. The kit is the first of its kind indigenously developed in the country and is a good substitute for imported technology in terms of cost effectiveness and easy availability.


Betanodavirus assay (NOVA) prototype kit


            Lane M            100 bp ladder

            Lane 1             Sample 1

            Lane 2             Sample 2

            Lane 3             Sample 3

            Lane 4             Positive control

            Lane 5             Negative control


Diagnosis of VNN using Betanodavirus assay (NOVA) kit


(Alternate photo of the kitOnly one may be selected  


Technology Transfer and Commercialization

CIBA is looking for entrepreneurs to design and scale up a marketable diagnostic kit for field level application in fish hatcheries, fish farms, PCR / quarantine labs and research institutions.

For details please contact:



(Indian Council of Agricultural Research)

75,Santhome High Road, R.A.Puram, Chennai – 600 028

Phone : 91-44-24617523 (Direct) 24616948, 24610565, 24610311

Fax No: 91-44-24610311   E- mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

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