The Super Soldier Serum was a formula developed by German Dr. Abraham Erskine and later semi-reproduced by Bruce Banner. It was responsible for the super-human abilities of Red Skull, Captain America, Bruce Banner and Emil Bromsky.
History
Erskine began developing his serum in 1930 while still in Germany, where the formula was first tested on SS soldier Johann Schmitt, turning him into Red Skull. Erskine would later describe to Steve Rodgers how the formula wasn't ready for use, and how the serum's personality amplifying effects made Schmitt into the evil man he became. After Erskine escaped to America, he joined the Strategic Scientific Reserve, the predecessor to SHEILD. There he took part in a project to create a supersoldier, Project Rebirth, 0and using Vita-Rays he successfully used the serum on Steve Rodgers, who became Captain America. Unfortunately, the scientist and the last vial of the successful serum was destroyed by HYDRA spy Heinz Kruger, with the last remnants of the serum remaining in Rodgers' DNA. (FILM: Captain America: The First Avenger)
In 2002, General Ross of SHEILD revived the Bio Force Enhancement Project, a secret project set-up after the relative failure of Project Rebirth. A failed attempt to reproduce the serum with added bouts of Gamma Radiation led to the accident that turned Bruce Banner into the Hulk. Banner was later forced to flee from SHEILD, who emploied ex-Soviet spy Emil Bromsky to track him down. General Ross, eager to sustain Bromsky's will to fight, gave him an injection of a different serum, which gave him abilities similar to those of Captain America. Later combination with the altered serum in Banner's blood turned Bromsky into The Abomination. (FILM: The Incredible Hulk)
As of 2011, it is unclear how much of the serum still exists or is in use. (FILM: The Avengers).
Effects
The raw serum's general properties seemed to be enhanced strength and senses, as well as emphasising the user's key personality traits. Johann Schmit's evil meant that the serum ripped the flesh from his skull, while Steve Rodgers' bravery enhanced his body to the peak of human ability. Emil Bromsky's strength and fast regenerative abilities were part of his love of fighting.
When saturated with Vita-Rays, the serum worked more successfully. Gamma rays were believed by Bruce Banner to work similarly, but instead corrupted the serum's effects and turned him into the raging monster known as the Hulk.