Use blood sampler | Chapter 4 - Dr Kessler DI Riptide Guide
Last update: 11 May 2016
Go to the machine on the right and press Action key. At the end talk with dr Kessler and he'll give you a tunnel map and few hints. Listen to radio talk with Harlow what ends this mission and takes you to the fifth chapter. Attention: before leaving BioSphere Laboratory take a reward from Kessler, which is a Taser.
Main quest unlocked: House of God (quest is automatically unlocked after finishing the described mission).
Sidequest unlocked: History Lesson (to unlock, talk with dr Kessler in BioSphere Laboratory).