Overview Function determining sequence for a desired DNA sample Process (Sanger/direct method) DNA sample put in 4 different reaction mixtures each contains all 4 deoxynucleotides, 1 different dideoxyneucleotide (ddNTP), and a DNA polymerase dideoxynucleotides stop DNA polymerization at each base generates DNA chains of various lengths that encompass the entire original sequence solutions are separated by gel electrophoresis sequence can be deduced by looking at each electrophoresis row and reading which ddNTP was added to that tube column Clinical use most commonly used when no specific set of mutations is a common cause of disease