An instrument for the controlled trimming of plastic specimen blocks for light and electron microscopy.

A device for the controlled trimming of plastic specimen blocks for light and electron microscopy is described. Many advantages of previously reported instruments together with 1) a rack and pinion control of knife movement, and 2) a control of rotation of the specimen block at 90 degrees, 180 degrees, 270 degrees, or 360 degrees are incorporated. In conjunction with an ocular micrometer, the device allows accurate removal of thin slices during trimming.