The quest for what are the truly elementary particles remains one of the crucial problems in physics at its most fundamental level. This work attempts to provide at least a partial answer to that question through the application of measurement techniques of extraordinarily high precision to the determination of properties of elementary particles in ion traps. In this instance the electron and the positron will be use. Determination of the g- factors of these two particles will serve as a test of how `identical` these two particles are. Results will have impact not only on the validity of CPT invariance, but will also serve as a severe test of QED theory.