A precision machine for mounting tissue for Mohs micrographic surgery.

Background: Mounting specimens onto chucks, so the cryostat knife follows the exact path of the surgeon's knife, poses difficulties even for experienced histotechnologists. Oftentimes, the frozen planar surface of the tissue falls at an angle that requires gimballing the chuck holder to compensate.

Objective: To demonstrate the use of a precision tissue mounting machine and associated fast freezing chucks.

Methods: Specimens of pickled pig skin were marked with blue dye on the cut surface. The pieces were mounted onto chucks with the blue surface exposed, and then sectioned in a cryostat.

Results: A complete section with all edges was obtained after eight turns of the cryostat handwheel, at 12 microns per turn.

Conclusions: A precision machine used in conjunction with a properly adjusted chuck holder can yield results unobtainable by other methods.