Infection of virus (such as nodavirus and iridovirus) and bacteria (such as Vibrio anguillarum) in farmed grouper has been widely reported and caused large economic losses to Taiwanese fish aquaculture industry since 1979. The multiplex assay was used to detect dual viral infection and showed that only nervous necrosis virus (NNV) can be detected till the end of experiments (100% mortality) once it appeared. In addition, iridovirus can be detected in a certain period of rearing. The results of real-time PCR and in situ PCR indicated that NNV, in fact, was not on the surface of the eggs but present in the embryo, which can continue to replicate during the embryo development. The virus may be vertically transmitted by packing into eggs during egg development (formation) or delivering into eggs by sperm during fertilization. The ozone treatment of eggs may fail to remove the virus, so a new strategy to prevent NNV is needed.

This study presents an integrated microfluidic system capable of automatically performing four reversetranscription polymerase chain reaction (RT-PCR) processes simultaneously for fast diagnosis of aquacultural diseases. This system integrates micro temperature control modules and a microfluidic control module. The micro temperature control modules have micro temperature sensors and array-type micro heaters that maintain precise and uniform temperature conditions for the RT-PCR processes. The microfluidic control module can automatically transport samples and reagents by using pneumatic micropumps, microvalves and microchannels. Moreover, by using random primers in the reverse-transcription (RT) process, the chip design is simplified and the consumption of RT products in the subsequent multiple polymerase chain reactions (PCR) is also minimized. After sample transport between the RT chamber and the PCR chambers is finished, the PCR process is then performed to amplify

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