The present invention relates to diagnosing glycogen storage diseases in mammals. In an alternative, a laser-imageable formulation suitable for spray application to a substrate, comprises a color-former, a binder and a carrier. In this tool, a restraining device is provided in order to hold the holding device in a defined position during a movement of the fastening tool housing. The bias voltages may be generated via a resistor ladder andor via the resistive nature of a portion of semiconductor substrate.