I remember watching this movie around 2008-2010. It's in English and perhaps a typical Hollywood movie. I only remember this part of the movie.
A man and a woman trapped in a room (maybe a storage room) have one injection and must choose who should be injected. Both are wounded, I think. Finally, the man receives the injection and his wounds are healed. The injection contains alien DNA of some sort. They study this alien.
The man is wearing military clothing and has guns. I think the woman was blonde and wore white clothing.