The question of particle charge is important because it acknowledges the active state of silver, the cation (Ag+). Many manufactured colloidal silvers are purposely or inadvertently bound into neutral silver compounds like silver salts and silver proteins. Mostly, this is done so that the water will hold higher ppm concentrations. However, throwing more silver into colloidal suspension (or dissolved solution, in the case of silver salts) does not necessarily result in greater benefit. When you have a preponderance of active silver (Ag+), you need very little to effect very powerful and positive changes within the biological milieu. For example, 10 parts-per-million of a predominantly active cation suspension can exert far more powerful effects than 500 parts-per-million silver colloids bound into neutral protein species. For the average consumer, even those well informed, colloidal silver is a ?blind? item. It?s hard to see what your body sees without magnifying colloids via electron microscopy by a factor of 100,000x or even greater. At that level, particle size can be measured and uniform dispersion would indicate active Ag+ content. A pure silver colloid, according to the Immunogenic Research Foundation, is evidenced by the presence of Ag+ that is uniform, picoscalar and oligodynamic (bio-active), which is more accurately referred to as Silver Hydrosol. Neutral silver particles, or silver containing the outermost electron, are not in a biologically active state.