The gaskets that are used with the RC-30 confocal imaging chamber come in three thicknesses: 150, 250 and 375 um.  Leaking is not uncommon when only a single150 um gasket is used. This is because the thinnest gasket allows little compression. We suggest using either a 250 um gasket or two 150 um gaskets (300um total thickness).

Alternatively, if the chamber is over-tightened, then the glass coverslips can warp slightly, leading to a leak.