I'm looking for a book title that I read a while back. The book was about a disease, I can't remember if the disease started in space, or on Earth; however the end result is that two astronauts remain quarantined on a space station where they were doing research for a cure. The reason the astronauts go to the space station is that initial research shows that the disease is less volatile in low gravity. In order to find the cure, it is determined that in some fashion DNA, RNA, or something to do with a certain type a toad can be used to neutralize the disease. I hope someone knows this title. My memory is a little hazy on the details, but I remember I enjoyed the book. Does Anyone Know This Title?