I read the paperback version but don't recall the name, only that the cover was primarily white. It's been at least 8 years since I read it, but the book may be a little older than that, 1995-2007?. It takes place in about the same time frame, as the setting, technology and procedures seem modern, not overtly futuristic nor noticeably in the past. The protagonist is a woman, middle age or slightly younger, who is an astronaut and biologist. The story starts on Earth describing the asteroid, how it was recovered from deep in the ocean, and the unknown black gelatinous masses contained within. It goes a little into studies performed, i.e., injected in frogs and mice - which the former comes back as a major plot point towards the end, as the aliens have a vulnerability to 'pregnancy hormones' from the frog DNA they integrated. Skipping the bulk of fluff to the memorable bits, she and her crew are sent to space with this payload of unknown gunk in vials and told to run test...