The invention relates to a method for describing a predetermined desired course with a beam of particles or waves, wherein a movable beam-directing device influences the direction of the beam, so that the latter describes an actual course. Another method includes etching the optical component in an etchant including fluoride and bi-fluoride ions. The biosensor can be a genetically modified cell that expresses luciferase as reporter gene. Useful high solubility borates includes boric acid, boric oxide, ammonium borate and alkali metal borates such as sodium borate. The trace packet can be used to analyze and debug communications flowing on a bus when the software module detects a problem.