From Bulbapedia, the community-driven Pokémon encyclopedia.
Red discovering Mewtwo in its tank
The Mewtwo Project was the name of a Team Rocket project in the Red, Blue, and Green arc of Pokémon Adventures. Its purpose was to artificially create the most powerful Pokémon ever by enhancing the DNA of Mew. Originally intending to just synthesize the DNA, it was discovered that there wasn't a sufficient amount. Blaine had to use cells from his own arm to complete Mewtwo, making them dependent upon each other, and causing Blaine to defect from Team Rocket after Mewtwo escaped. They did not get the Mew Disc. Most of the scientists involved in the project were killed when Mewtwo destroyed the Cinnabar Lab in And Mewtwo Too!?.