Petra delivered the large box of samples to the lab. Micro already unpacked them into the sample container.
According to Micro you would need to find out the odd one out. They are remains of Jimmy Hoffa, except one.
This is the low-spoiler guide for "Bogus sample" puzzle in Mutropolis. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.