It’s right after a boss fight in Chapter 5
Who doesn’t love a classic survival horror “big bad that you need to burn/freeze” puzzle-like boss fight? Dead Space has at least one of them at the end of Chapter 5, which leads directly into the Premeditated Malpractice side mission. Here’s how to start it with the Tissue Sample, and where to scan it.
After freezing the boss in Chapter 5, you’ll have access to the Tissue Sample
Following the boss fight with the “Hunter” enemy (that keeps regenerating), you’ll be able to loot its body and grab the “Tissue Sample.” From here, there’s a really easy trick to use to figure out where to actually bring the sample.
Open up the missions menu, then scroll to the “Scan Tissue Sample” side mission. Select it, then track it. From then on, you’ll be able to press the navigation button (R3 but default) to bring up a breadcrumb trail. Note that this trail is orange, and can diverge from the blue “main objective” trail.
How to scan the Tissue Sample (Tissue Sample Needed) and complete the Dead Space remake Premeditated Malpractice mission
After you’ve selected the Premeditated Malpractice side mission, you’ll be able to track the path straight to the scanner. The scanner can be found in the main lab, which you’ve already come across as part of the main story.
Follow the orange line and backtrack through the medical facility into the main lab. On the bottom floor tucked away in the northeast corner, you’ll find the scanner. Interact with it while you have the Tissue Sample and the side mission will pop.
If you come across the scanner before you grab the Tissue Sample (read: before the end of Chapter 5), you won’t be able to use it. Make a note of where it is so you have an easier time finding it down the road!