I have them done, it is not expensive. If you want to do it your self, call your local vet and find out who is the lab in your area that does it. Then follow there protocol. Good luck!
Hannah, there are 2 places I know of that the vets here send to. One in Wash. state and one in either Athens or Augusta Ga. The place my vet sent to was here in Ga. Bit I have heard the one in Wash. is way better. But it takes longer to get results.