Blood for the Baron!

Soundwave: Hulk, release the samples.
Hulk: Hulk open funny jar.

The Hulk drops the container in order to allow the symbiotes to reach Optimus.
Soundwave: Be careful, Hulk. We have only three samples, and we cannot be sure if any of them will go after Optimus Prime.

One sample goes to the police van. Reflector quickly stands up to avoid the Symbiote.
Reflector: Ewww.

another sample goes after the unconscious Spider-Man.
Soundwave: That could give good results, but is not what we need right now.

The last symbiote reaches the intended target: Optimus Prime.
Soundwave: Now the symbiote will make you become...

Soundwave: ...the perfect Decepticon leader.

Optimus struggles to avoid the symbiote's corrupting influence.
Frenzy: Ya want to get ridda your new paintjob? Nah way! Ah'm gonna stun ya to avoid it!
Frenzy uses his sonics against Optimus, which accidentally causes the symbiote to wear out.
Soundwave: Negative, Frenzy. Stop right now.
Frenzy: Whoops. Sorry, Big Brothah.

Reflector: I have photographic evidence of how did you mess everything, Frenzy! See you. I don't intend to stay fighting and be kicked.
Soundwave: Skywarp, recover the last sample. It is still useful.
Skywarp: Yes, Soundwave.

Skywarp puts the symbiote back into the container.
Soundwave: Well done, Skywarp.

Soundwave: Decepticons, retreat.
Most of the Decepticons, aside from Buzzsaw and Laserbeak, transform to their altmodes.