This is Roper bringing you a complete 100% walkthrough of Hitman: Absolution. This video will get you the following challenges in level 12, Death Factory:

Chameleon
Evidence Collector
Infiltrator
Suit Only 
Good Test Results
The Abyss Gazes Back
The Common Good
Scientific Thoroughness
Happy Birthday
In the Right Space
The Shock Doctrine
Eureka
Doctor in the House
Strap Him In
Unseen
Experimenting
Research and Hidings 
Ground Zero
Reap What You Sow Part 1 
Reap What You Sow Part 2