I suggest that developers add an explanation to the DNA Manipulator interface that for the device to work, all the cells on the right must be filled, and nothing else, but only one Tree bark, one Mutagen and one Seed. Without this prompt, nothing tells the player that the combinations of resources to create tree seedlings should be exactly that. And, you see, this is strange in a situation where the protagonist himself designed and assembled this device (not knowing exactly how it will work, and why it has exactly three cells).

The DNA Manipulator has two screens look at the one above for recipes.