A techno-organic virus (also known as T-O virus) is a fictional virus appearing in American comic books published by Marvel Comics. The virus transforms organic material into techno-organic material. Techno-organic material resembles both machinery and living tissue. All techno-organic cells function like independent machines and carry both the virus and all information on their carriers, including memories and appearance. This allows a techno-organic being to rebuild itself from a single cell when destroyed.
There are two known variants of this disease in the Marvel Universe: the virus carried by the Technarchy, known as the Transmode Virus, and the variant created or discovered by Apocalypse.
The Transmode virus is used by members of the Technarchy to turn other beings into techno-organic beings. The Technarchy can then feed upon the infected beings and drain their energy (visible as lights flowing through the infected creature). Once the energy has been drained, all that remains of their prey are brittle statues. If an infected creature is not drained of its energy, it becomes a Phalanx. Transmode-infected creatures are usually black and yellow, although they can change their color.
The Transmode Virus is highly virulent. It can transmit via skin contact (though a Technarch can prevent transmission) and will transform a creature into a techno-organic creature within seconds. Only mutants have some resistance to the virus. For instance, Doug Ramsey was infected with the virus, but his infection only progressed very slowly and he was unaware he had been infected. This may have been caused by either his own mutant facility with computer code preventing the virus from infecting him at the usual rate, or a side-effect of the fact he was not infected in the usual manner, but had picked it up after repeatedly fusing his body and genetic code with that of the Technarch Warlock.
An infected creature also gains the ability to shapeshift. They can quickly restore themselves when damaged and can interface directly with machinery. While Technarchs feed by draining other techno-organic beings, Phalanxes have the ability to directly absorb matter (both organic and inorganic).