Application of a fluorescence stereomicroscope as an in-line detection unit for electrophoretic separation of bacteria

Electrophoretic separation of bacteria as well as potential applications of electrophoresis in microbiological medical analysis has gained the interest of several research groups. The undesired effects such as aggregation and/or adhesion of the cells have a strong effect on the separation process. For a better understanding of the phenomena we decided to apply a fluorescence stereomicroscope as an in-line detection unit for observation of electrophoresis of microorganisms. The microscope was connected to the capillary electrophoretic system which allowed observing the moving bacteria through a 10 cm wide window created in the capillary that was kept in a special holder. The experiments showed that the stained bacteria adhered to the inner capillary surface thus creating a green fluorescent layer. The short (2 mm) polymeric monolithic bed, the pore size of which disabled bacteria cells to pass through, was also photosynthesized in the centre of the window and served to preconcentrate the bacterial suspension.