apparatus has been designed to prepare pieces of animal tissues for
metabolic experiments and to be especially applicable to small and
irregular specimens available at biopsy or from small organs.
Its special features are to cause much less disturbance of cell
structure than homogenizes or blenders, and to be applicable to
fragments which would be difficult or impossible to cut by ordinary
methods. It has been applied to liver, kidney and various parts of the
central nervous system.
action of the machine is as follows: a circular stainless steel table,
on which the specimen is placed, is traversed automatically and at a
speed which can be varied, from left to right of the machine.
At the same time a chopping arm carrying a blade is raised and
dropped by its own weight and the tension of a spring, at speeds
varying from zero to a maximum of 200 strokes per minute.
up to 1 mm. thick and cubes or prisms up to 1 mm. 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 an indexing clutch in conjunction
with a micrometer head, the latter being calibrated in microns.