- "Bruce, this is all you! You didn't send me much to work with, so I had to concentrate it and make more. With a little more trial and error, there's no end to what we can do! This is potentially Olympian! This gamma technology has limitless applications. We'll unlock hundreds of cures. We will make humans impervious to disease!"
- ―Samuel Sterns unveils his plans
Samuel Sterns is a cellular biologist and Grayburn College professor who was finding a cure for Bruce Banner. Sterns managed to engineer a temporary antidote for Banner's condition, but was also forced to repeat this process with Emil Blonsky, transforming him into the Abomination. When he was affected by Banner's blood on his head's open wound, his mind suffered a rapid mutation, greatly increasing his mental abilities. However, Natasha Romanoff arrived and subdued him, handing him into S.H.I.E.L.D.'s custody.
Helping Bruce Banner
Dr. Samuel Sterns was a Professor at Grayburn College, teaching in the department of Cellular Biology. When Bruce Banner went on the run from the United States Armed Forces, led by General Thaddeus Ross, he managed to establish contact with Sterns and they communicated with each other as Mr. Blue and Mr. Green, respectively, while collaborating to find a cure for Banner's condition.
When Banner was in Brazil, Sterns suggested to search for flowers, but when they failed to create a plausible antidote, Sterns asked Banner to send him a sample of his blood so he could engineer an antidote for himself. However, Sterns kept his true intentions secret from Banner: Sterns in reality had desired to use the antidote to create cures to various illnesses, motivated by the goal to make humans practically immune to any genetic disease. However, Sterns' plan was flawed, as he had underestimated the blood toxicity of Banner's blood. 
Engineering an Antidote
Meeting in the Flesh
- "What I'm saying is, if we overshoot this even by the smallest integer, we could be dealing with concentrations of extreme amounts of toxicity."
- ―Samuel Sterns
Sterns was walking out of a building on the campus of Grayburn College when he was confronted by Professor Elizabeth Ross of Culver University. Sterns recognized her close to instantly, and she began introducing him to Bruce Banner, who revealed himself to be Mr. Green.
Sterns expressed his excitement to cooperate with Banner and Ross, explaining that he contemplated on if Banner was real and how he could live with the Hulk, caged inside his body. When Sterns began monologuing, Ross and Banner insisted that Sterns stay on task. Sterns explained to Banner that in order for the antidote to work, they need a precise set amount of blood to create the suppressant, or it would not work otherwise.
- "Bruce, this is all you! You didn't send me much to work with, so I had to concentrate it and make more. With a little more trial and error, there's no end to what we can do!"
- ―Sterns unveils his plans
After witnessing Banner transform into the Hulk as a test and successfully reverting him back with their finalized suppressant, it was revealed that he had been experimenting with Banner's blood samples on animal test subjects without his knowledge. Sterns argued with Banner, and during the argument, the Strategic Operations Command Center had found them.
Creating an Abomination
- "You've seen what he becomes, right?"
"I have. And it's beautiful. Godlike."
- ―Emil Blonsky and Samuel Sterns
With Banner and Ross taken into the custody of Thaddeus Ross, only Sterns remained inside the building. Major Kathleen Sparr, General Ross' assistant interrogated Sterns about his experiments with Banner's blood, but Sterns explained that he couldn't replicate the "Hulk" monster that Banner could turn into, even with the mass amount of blood samples he received from Banner. When Sparr began to respond to the revelation that the Hulk could not be replicated, Emil Blonsky, who was still inside the building killed Sparr with blunt force.
After the power hungry Blonsky opened up on his true thoughts on Sparr, he turned a gun on a confused Sterns and threatened him to comply with his demands to inject him with Banner's blood. Sterns opened up on his experiment with Banner, but also noticed that Blonsky was already injected with a second serum. Blonsky eventually managed to force Sterns to comply by physically threatening him.
- "This is what I was trying to explain. I don't know what you've been ladling into yourself. But clearly it worked. Let's assume you don't understand a word I'm saying, but if you'll just get back on the table, I can fix this!"
- ―Samuel Sterns to Emil Blonsky
Sterns began setting up the procedure, and strapped Blonsky to the rest. When Sterns injected the power-hungry Blonsky with Banner's blood, Sterns watched Blonsky growl. Despite pleading for him to stay on the rest, Blonsky mutated into a brown, spiky Abomination. Embracing his newfound powers, Blonsky threw Sterns onto the floor and trashed the lab.
In the confusion, Sterns was accidentally infected with Banner's blood via an open wound on his forehead and his head started expanding as he smiled with joy, while the Abomination began a rampage on the streets of Harlem, massacring the local police force and the United States Armed Forces soldiers.
Standoff with Natasha Romanoff
- "Dr. Samuel Sterns?"
"I think perhaps once I was...but shall now become much more."
- ―Natasha Romanoff and Samuel Sterns
Sterns' mutation went wild, and his brain power incremented exponentially. He was found by Natasha Romanoff, who had a brief dialogue with him, during which Sterns identified Black Widow's birth place from a hint of accent in her voice. Sterns then attempted to bribe her, promising he would help her come back to Stalingrad, but Widow shot him the leg and arrested him.
- Master Scientist: Samuel Sterns helped Bruce Banner when he sought a cure for his transformation into Hulk. He was able to develop a method that could potentially reverse the transformation, by duplicating and testing the limited blood samples that Banner sent him. He was also able to duplicate the transformation process with Emil Blonsky, transforming him into Abomination when Banner's blood was mixed with the Super Soldier Serum that Blonsky already had, a situation that Sterns had already anticipated. After Sterns' mutation, his intellect increased, but he was immediately imprisoned.
Video Game Only
- In the comics, Sterns was not a scientist, but instead was a menial laborer with only average intelligence. He was exposed to gamma radiation while he was transporting hazardous materials. He also became the superpowered criminal Leader before Banner became the Hulk.
- Sterns uses the online name Mr. Blue to communicate with Banner. In the comics, Mr. Blue was an alias used by Betty Ross to keep in contact with a fugitive Banner.