DNA

DNA, or scientifically known as DeoxyriboNucleic Acid, is the genetic makeup found in all living beings; it essentially is used to program the being, giving them a specific, yet unique personality, appearance, and so on.

This is also an essential part of cloning, and in this case, the Grand Army of the Republic's clone army. During the reign of the Empire, the Imperial clones discover that there was a traitor among their ranks, working for the seemingly peaceful Kaminoans. During the Kamino Uprising, the Stormtroopers were ordered to take the DNA sample from the facility to stop the traitorous clone production.