An apparatus for the application of one or more biological samples to an electrophoretic support is described. This apparatus features one or more planar projecting elements made of polyvinylidine difluoride or polysulfone having a perforated circular orifice within each projecting element for sample...http://www.google.com/patents/US5405516?utm_source=gb-gplus-sharePatent US5405516 - Apparatus for the application of biological samples to an electrophoretic slab support
