"DNA" is the second episode of science fiction sit-com Red Dwarf Series IV and the twentieth episode in the series run. It was first broadcast on the British television channel BBC2 on 21 February 1991, although it was planned to be broadcast as the fifth episode, it was moved forward in the schedule by the BBC. Written by Rob Grant and Doug Naylor, and directed by Ed Bye, the episode revolves around the genetic engineering technology that the crew discover.
Kryten is ecstatic being human, but soon discovers the downside - having no zoom-function in his eyes, his nipples don't work and he has a particularly ugly appendage. Being human soon loses its charm and, having insulted his own spare heads, Kryten decides to revert to his old self.
Whilst preparing the DNA modifier console, Holly suggests they try the device on a test subject. Lister has a mutton vindaloo dish on hand and places the tray in the beam, however this creates a "mutton vindaloo beast". It seems indestructible as their bazookoid blasts have no effect on it. They have little choice but to run off, but it won't be long before it finds them. So that they can defeat the beast, Lister asks Holly to turn him into a "super human — man plus". It nearly works as he becomes a Lister/Robot hybrid but he is also shrunk to about one foot in size. Lister, inadvertently discovers that a spilt Lager can inflicts pain to the beast as it stands on the liquid. Using this knowledge Lister throws a can of Lager into its mouth, shoots the can and the monster explodes in a shower of Vindaloo.
With the tail end of production and finances running low the DNA ship's set was rushed and was not as had been expected. However the grungy looking corridors and rooms were better than nothing which may have been the case.
Paul McGuinness, a member of the effects team, wore the Vindaloo Mutant outfit. He also produced the three-headed corpse that Kryten and Rimmer discover onboard the DNA ship. Richard Ridings voices the D.N.A. Ship Computer.
Blue-screen techniques was used to produce the transformation of Lister to a one foot tall "super-human" man plus. Craig Charles was shot in front of a bluescreen to make his self appear one foot tall while this was added to the other crew's footage, who were also involved in blue screen, as they run by the small Lister.
Lister cites Descartes who said, "I am what I am", but Rimmer thinks that it is Popeye the Sailor Man. When Lister is being chased by the vindaloo mutation he parodies Bruce Willis' line from Die Hard 2 (1990); "How can the same smeg happen to the same guy twice?" Referencing the previous series when he was attacked by what he thought to be a Shami Kebab in "Polymorph".
Using the DNA modifier Holly turns Lister into a super-human fighting machine "Man Plus". The result transforms Lister into a small replica hybrid of Robocop from the 1987 film of the same name. Jaws is then parodied in the final scene when Lister disposes of the vindaloo mutation by throwing a lager can into its mouth and then shooting at the can, making it explode along with the mutation.
The episode was considered to be one of the better episodes from the fourth series, however it did receive some criticism for moving the humour away from the characters and into situation-based comedy.