A laser core is a vital component of Transformer anatomy. If a Transformer's laser core is extinguished, the Transformer will cease functioning.
It's been heavily debated what role the laser core and the spark play within a Transformer. Some fans have speculated that the laser core may be some sort of housing unit for the spark. Others have speculated that it may be a separate entity. Mechatron's on-package bio says he possesses an upgraded spark capture device which can rip the laser core out of any Transformer, seemingly confirming that the laser core is a housing unit. Additionally, Primal Prime's bio makes reference to the character's laser core housing his personality.