This episode was followed by a sequel: The Origin of Species (1998). Ron Rifkin (Dr. Martin Nodel, though his first name was given as Eric in that episode), Ryan Reynolds (Paul Nodel), Kathleen Duborg (Hope), William deVry (Ben), Tara Spencer-Nairn (Heather), Kirby Morrow (Kirby), Silvio Pollio (Anthony) and Terri Lynn Ibisoglu (Sarah) all reprised their roles in that episode.
Per the title, the shape of a double helix is of a twisted ladder configuration and who's most often used reference is to the shape and structure of DNA that was first published by James D. Watson and Francis Crick in 1953.