Stark Labs is a Stark Industries research facility.
The scientists at Stark Labs studied Iso-8 with the aim of discovering its capabilities. When R.A.I.D. attacked the facility, they took several hostages and intended to steal the Iso-8. Captain America was sent in to deal with the situation. Maria Hill contacted Tony Stark, who was two continents away, and informed him of the attack. While Stark was not pleased with the news, he was relieved to hear that Cap was on the job. Cap successfully rescued the hostages and retrieved the Iso-8.