Sanger Sequencing (2D Gel): Chain Termination & Electrophoresis

This simulator models the classic dideoxy chain-termination method that first made genome sequencing possible, in the flat four-lane gel layout it was originally read from. A DNA template — random or typed in by hand — is split into four dideoxy termination reactions, one per base, each producing every fragment that ends in its own base. Those fragments are loaded into a 2D gel and pulled by an electric field through a sieving matrix, where mobility scales inversely with fragment length — short fragments race ahead down every lane, long ones lag behind. A detector line low in the gel calls each fragment's lane (base) the instant it's crossed, shortest first, live-reconstructing the sequence exactly the way the original manually-read Sanger gels worked. Template length and field strength are both adjustable, exposing the real speed-versus-resolution trade-off that governs actual gel electrophoresis runs.