Its special features are to cause much less disturbance of cell structure than homogenisers or blenders and to be applicable to fragments that would be difficult or impossible to cut by ordinary methods. Typical applications are to liver, kidney and various parts of the central nervous system.

Slices up to 1mm thick and cubes and prisms up to 1mm cross section can be prepared with the chopper in 30 seconds. Provision is made for stepless variation of slice thickness from zero to the maximum by means of a micrometer head calibrated in microns.

The action of the machine is as follows: a circular stainless steel table, on which the specimen is placed, is traversed automatically from left to right of the machine. At the same time a chopping arm carrying a blade is raised and dropped rapidly by an adjustable force. As the table carrying the tissue passes under the blade it is chopped into the required slices. If prisms are required the table is returned to the left hand side of the machine, turned through 45 degrees, and the process repeated. Cubes are formed by rotating the table 90 degrees. The cutting speed can be varied from zero to over 200 strokes per minute. A safety limit switch is provided to prevent the machine overrunning and a quick release mechanism for the return of the table.