If there are voids at the base of a vertical gel, bubbles can be trapped when the gel cassette is placed in the running buffer. These bubbles will cause an uneven electrical field and poor gel performance. Galileo vertical gel systems feature a cast-in-place system that that forms a smooth, flush seal at the bottom of the gel cassette. This allows for full filling and polymerization (no oxygen exposure) along the bottom edge of the gel, preventing any voids which would trap air and cause bottom bubbles.