New cryoultramicrotome with a feedback-advance system.

Cryoultramicrotomy is gaining in significance and use as technical improvements are made. In comparison with epoxy resin procedures, cryopreparations are more rapid; there is only a negligible loss of material and thus antigenicity is well preserved. The present work contains some newly developed details for the exact determination of the advancement of the sample in the direction of the knife in a microtome. It is a software-controlled ultramicrotome advance drive system with feedback regulation as well as repeatedly patented devices for advancement sensors.