The Gene Bomb was a device secretly created by a renegade Dominator scientist of low caste in the Alien Alliance during their invasion of Earth to negate the effects of the metagene and disable the powers of dormant and active metahumans.
History
This effect was never truly desired by the rogue insurgents' superiors, as they wished to harvest the genetic anomaly for their own ends. When the Gene Bomb was detonated, the active metahumans lost control of their powers and eventually fell into comas. The only metahuman to die as a result of the Gene Bomb was Scott Fischer of the Doom Patrol, due to complications from his leukemia. Other metahumans, including the Doom Patrol's Negative Woman, permanently lost their powers.
The Gene Bomb had the side effect of jump-starting latent metagenes within a small number of humans across the world (including Max Lord and Crazy Jane), as well as resurrecting the deceased Metamorpho, who had died in the recent Millennium event. It also boosted the power of other metahumans, such as Fire and Brainiac.
The effects of the Gene Bomb were reversed when the Martian Manhunter read the mind of the scientist who created it and concocted an antidote with the help of Doc of the Omega Men.