Detection of Salmonella Enterica in Egg Yolk by PCR on a Microfluidic Disc Device Using Immunomagnetic Beads Salmonella enterica is a pathogenic bacterium that causes foodborne illness. One of the vehicle foods of S. enterica are chicken eggs. Efficient collection of the bacterium is necessary to detect it specifically. We developed a method to detect S. enterica by PCR on a microfluidic disc device using a fluorescent probe. Salmonella enterica cells were isolated in the microchambers on the device, followed by thermal lysis and PCR targeting with the invA gene, a gene specific to S. enterica, were observed by measurement of the fluorescent signal that resulted from gene amplification. However, the developed method was unable to discriminate viable cells from dead cells. Consequently, in this study, magnetic beads modified with antiSalmonella antibody were utilized to detect viable Salmonella cells from egg yolk prior to PCR on the device. While using the antibodymodified beads, egg yolk components, which inhibit PCR, were removed. The collected cells were subsequently detected by PCR of the invA gene on a microfluidic disc device. This method enabled the detection of viable cells without the inhibition of PCR by any egg component. S. enterica was detected at 5.0xc3x97104 cells mLxe2x88x921 or at a higher concentration of egg yolk within 6 h including the sampling time.

Immunosensor Based on LongPeriod Fiber Gratings for Detection of Viruses Causing Gastroenteritis Since the norovirus is the main cause of acute gastroenteritis all over the world, its fast detection is crucial in medical diagnostics. In this work, a rapid, sensitive, and selective optical fiber biosensor for the detection of norovirus viruslike particles (VLPs) is reported. The sensor is based on highly sensitive longperiod fiber gratings (LPFGs) coated with antibodies against the main coat protein of the norovirus. Several modification methods were verified to obtain reliable immobilization of protein receptors on the LPFG surface. We were able to detect 1 ngmL norovirus VLPs in a 40min assay in a labelfree manner. Thanks to the application of an optical fiber as the sensor, there is a possibility to increase the userxe2x80x99s safety by separating the measurement point from the signal processing setup. Moreover, our sensor is small and light, and the proposed assay is straightforward. The designed LPFGbased biosensor could be applied in both fast norovirus detection and in vaccine testing.