In the beginning of The Dark Knight Rises, Bane and his minions take over the airplane in which Dr. Pavel is transported. After having the control over the airplane, and having it wired up with cables, they bring in a body bag in which a seemingly dead person lies in. Then, they start a blood transfer with Dr. Pavel.
But why? I guess they want, when the bodies are found, the body-bag-person will be identified as Pavel. I am sure that this little blood would not be enough, it only took some seconds. Is there any other reason or explanation?