The present invention provides devices, apparatuses and methods for automated processing of biological samples. This invention provides automated devices and automated methods of sequentially treating a biological sample with processing fluids in more than one washing basin. In some embodiments, the invention provides automated devices and automated methods of western blot processing. In some embodiments, the invention provides automated devices and automated methods of Southern blot processing. In some embodiments, the invention provides automated devices and automated methods of northern blot processing. In some embodiments, the invention provides automated devices and automated methods of staining biomolecules on solid supports. In some embodiments, the invention provides automated devices and automated methods of nucleic acid separation and isolation.