The colloidal particles are electrically charged and they carry the same type of charge, that is, either the colloids are negatively charged or positively charged. The existence of charge on the colloidal particles is inferred from the observation that the colloidal particles move either towards the cathode or anode when the colloidal sol is placed in an electric field. This phenomenon of charged particles moving towards the oppositely charged electrodes in the presence of an electric field is called electrophoresis.Electrophoresis is carried out by placing the colloidal solution in a U tube which is fitted with platinum electrodes.
With electrophoresis we can determine the charge of colloid, its can b use to identification DNA of bomber suicides.
