CNA

CNA—standing variously for Cyber/Nano Algorithms and/or Cybernucleic Acid—is the genetic material that determines what Transformers are like. Tinkering with this material can be dangerous and can have long-lasting, negative effects. CNA contains a Transformer's hard-coded design schematics, which, like genetic data, appear to be stored in the spark itself.

It is sometimes known as Sourcecode.

Marvel Generation 2 comic
The existence of Transformer genetic material was mentioned and seen when Perceptor and others analyzed the Swarm. They noted that its genetic material and cellular structure were identical to that of the Transformers species.

Regeneration One
Scorponok discovered a strand of CNA he referred to as the 'warrior gene' which he claimed was the difference between Autobots and Decepticons. He also a created the Gene Key, a device that could re-write CNA and activate the gene. Although Scorponok explained that Autobot and Decepticon are not so black-and-white, the Autobot Headmasters he tested the Key on displayed more aggression and were willing to follow Decepticon orders. The Autobot Perceptor was also affected by the Key, after which he showed signs of sadism.

2005 IDW continuity
Attempting to introduce other genders back to Cybertron, Jhiaxus altered the CNA of Arcee in order to change her physicality into that of a woman. His malicious lack of after-care and deceit in convincing Arcee into this "experiment" (Arcee later finding out that this process was unnecessary to transition thanks to Anode) definitely never came back to bite him in the ass, no sir...

Animated cartoon
Scalpel used the CNA of Perceptor as a template to make Magnificus as a part of Operation: Doppelgänger. Later, Starscream created many clones of himself.

Swindle was able to use the CNA of one of Starscream's clones to create two more that he used as enforcers.

IDW Aligned comics
Shockwave mixed dinosaur DNA with the Lightning Strike Coalition's CNA in his successful experiments with giving them new dinosaur alternate modes.

Hunt the Beasts
After the Predacons broke out of Shockwave's laboratory, you were sent on a mission to scout the place out and investigate what happened. During your search you discovered CNA samples of eleven different Predacons which provided valuable information about them. You also discovered that the Predacons were cloned by Shockwave using CNA samples he discovered of the long dead creatures.

Prime cartoon
As the Great War began to spill off Cybertron, both sides began seeding energon deposits on other planets. To protect Decepticon investments, Shockwave used the fossilized CNA of several Predacons to create a legion of enforcers. During his exile on Cybertron, he used the CNA to create Predaking, another Predacon clone.

After Starscream had cloned himself, he despaired that his CNA had not only given the clones the genetic instructions needed for transformation cogs, but that the binary bonding meant he felt all their pain.

The CNA was later used to rebuild Cybertron after it was mixed with a stabilized form of Synthetic Energon. The mixture, known as Cybermatter, revived Cybertron and allowed Cybertronians to return to their damaged home world.

Beast Wars: Uprising
After Lio Convoy started a rebellion against the Builders of Cybertron, his mentor Eject avoided a death sentence by proposing a solution: use Lio Convoy's CNA to create a clone army infused with the power of an Energon Matrix. The Builder Assembly approved of the idea.

Ask Vector Prime
There was much overlap between the hard-coded design schematics of Unicron's sleeper agents the Egg Beasts and his Dead End antibodies.