How do use the radiation in mutate the hamster

I've never heard of Mutate The Hamster, but I'm guessing you mean Mutate The Labrat, or Mutate The Labrat is similar to Mutate The Hamster. But here's what I know about the radiation.
You have to use the radiation a bit at a time or else the rat will die. Plus, you have to constantly feed it until the radiation wares off, and make sure that there is no other chemicals in its system (like mutagen X) or else the toxication will be too high, and it will die.
I hope that helped.