Abstract: A plate assembly for performing multiple filtrations with the use of a vacuum offers advantages for small samples due to the construction of its component plates, which include an upper plate with apertures forming sample wells, a membrane sheet forming the floor of each well, a collection plate with individual wells underneath the membrane sheet, aligned with the upper plate apertures, and a drop guide plate between the membrane sheet and the collection plate to guide and force small quantities of liquid downward from the membrane into the collection wells. The arrangement permits extremely small quantities of species on the membrane to be drawn into the collection wells without dilution, and avoids cross contamination between collection wells.

Abstract: Electrophoretic separation in a slab gel and blotting of the resulting zone pattern onto a membrane are both performed in a single tank cell which contains separation electrodes along opposing vertical walls and blotting electrodes horizontally arranged above and below the level designated for the gel placement. The blotting electrode situated below the gel is an array of parallel wires arranged to simulate a plate electrode. The cell is operated in separatory and blotting modes, in which the separation and blotting electrodes, respectively, are separately energized. During the separatory mode, the wires in the array forming the lower blotting electrode are electrically isolated from each other to permit each to adjust to the voltage of the buffer immediately surrounding it.

Abstract: An apparatus for drying gel slabs which includes a porous support pad resting in a recess, a flexible vacuum-retaining cover sheet covering the support pad and the periphery of the recess, and means for pulling a vacuum down from underneath the support pad, is improved by adding a perimeter groove around the periphery of the recess, preferably spaced a small distance therefrom, with channels connecting the groove to the recess to transmit the vacuum. The perimeter groove provides a faster distribution of the vacuum, and provides a further means of sealing the cover sheet around the periphery of the recess, to provide more even and more reliable gel drying.

Abstract: A gel used for electrophoresis is cast in a gel enclosure in which the gel will ultimately be used during the electrophoresis, by a novel method and using novel apparatus which provide for quick assembly and avoidance of leaks. The method and apparatus involve a wettable, preferably porous, membrane such as filter paper, which is thoroughly wetted with gel forming solution, then placed over the bottom opening of the gel enclosure and held in place until the gel on the membrane sets. Sealing of any cracks, gaps or irregularities along the rim of the opening is thereby achieved by the capillary action of the gel forming solution. The enclosure itself is then filled with gel forming solution. Once the latter has set, the membrane is removed.

Abstract: An integrated plate structure provides a novel component for use in an electrophoretic sequencing cell. The integrated plate structure consists of a glass plate and a plastic plate bonded together along a raised edge of the latter, the edge extending along the sides and bottom of the plastic plate. The plates thus form a permanent enclosure for an upper buffer solution, open at the top for filling. The glass plate further serves as one of the two glass plates forming the gel enclosure.

Abstract: An apparatus for drying gel slabs supplies heat to a horizontal gel slab from a heating plate above the slab, while drawing a vacuum beneath. The heating plate is weighted and has a flat lower surface at least coextensive with the gel slab. The slab itself is placed on a porous support pad in a vacuum chamber enclosed at the top with a flexible cover which clings to the gel and seals to the perimeter of the chamber when a vacuum is applied from below. The heating plate rests on top of the cover under gravitational force, providing even heating across the entire expanse of the gel slab and for the entire duration of the drying process, resulting in a continuous and uniform vapor flow downward from the gel slab, a minimization of internal stresses, and reduced susceptibility of the gel to cracking.

Abstract: A biochemical test plate assembly is disclosed for use in both filter assays and fluid retention applications. The assembly comprises an upper template with a plurality of discrete apertures, a continuous microporous film underlying the upper template, a gasket underlying the microporous film with apertures matching those of the upper template, a lower template underlying the gasket with a similar array of apertures matching those of both the upper template and the gasket, each aperture terminating at its upper end in a flat boss, and a base plate having a central recess to define an enclosed chamber when the base plate and lower template are in contact, the base plate being designed to form an air-tight seal between it and the lower template.