The bands of the gel are detected, and then the sequence is read from the bottom of the gel to the top, including bands in all four lanes. For instance, if the lowest band across all four lanes ...

Sanger sequencing (left) sequences 500-700 bases per reaction with 16 reactions per gel. Massively parallel DNA sequencing (center) sequences 100-5,000 bases per reaction with 10 thousand to 10 ...