A battery pack includes a battery cell, a circuit board, and a holder. Also provided is a method for selective breeding of dogs and kits useful for carrying out the methods of the invention. In one embodiment the size and spacing of the microspots on the substrate may be controlled by using an electrodynamic balance during the deposition step. At least one range for the at least one parameter that will be accepted by the server and not be accepted by the client is discovered.