First off, he's Mr.Blue, the guy who Banner was corresponding with from the beginning of the script, and the guy who Banner took the risk of sending a sample of his blood too.
Come halfway in the script, page 49, we are introduced to him, Betty and Banner are talking about him, he's an Anarchist, albeit a brilliant one.
Later on we see he's been doing quite a big of experimentation with the blood, we'll get to see some hulked out lab creatures... Not green, but grey... I think this plays into the fact that they can't get it just right.
Sterns is very excited about this, he has Nobel prizes on the mind.
Forget what happens after, but eventually the super soldier Blonsky gets a hold of him, demands to be injected with whatever Hulk concoction Sterns has made, something happens, I forget, next thing you know he's dead, and blood from the station where Blonsky transformed is dripping into his mouth... Something like that...
Infected blood? I think so.