This gasket is used on the Dr. Oligo 96 / 192 and Dr. Oligo 192e only when these instruments have the "Elution Option" installed. This is used on all Dr. Oligo 192c instruments. This is the 3mm thick gasket whose function is to seal the bottom of the 96 well plate.
If one is using a synthesis plate that has all 96 wells built into the plate (usually a disposable plate) in an instrument that has this gasket, they must use Clear Silicon Sealer (Sometimes called RTV) to seal this gasket into the instrument. If a sealer is not used, the edge of the synthesis plate can get between the synthesis box and the gasket so that the gasket is forced into the hollow bottom of the synthesis plate which results in some synthesis plates not sealing.
If one is using a column rack to hold individual synthesis columns in an instrument that uses this gasket, they do not need to seal or glue the gasket into the instrument.
This gasket is not used in standard Dr. Oligo 96, 192 or 192e.
This gasket is not used in the Dr. Oligo XLc systems.