An inexpensive "silicone photo device" for transmicroscopic registration of rhythmical movement phenomena.

A highly sensitive electronic unit (called "silicon photo probe") is described, which enables registration of cellular motion phenomena simultaneous with their light microscopic observation. Changes in light intensity caused by movements of the living object are registered by means of a silicon photo diode (silicon blue cell), which can be mounted within the binocular tube of any type of light microscope replacing one of the oculars. Its application during investigations of oscillating contraction activity in Physarum is reported. Advantages and short-comings are discussed with respect to established photometric, tensiometric and infrared registration techniques.