A completed sequencing reaction contains an array of colored DNA fragments. The shortest fragments correspond to the length of the primer plus one dye-colored base. The longest fragments are usually between 500 and 800 bases long, depending on when the sequencing reaction ran out of steam. The products of sequencing reactions are fed into an automated sequencing machine. Automated sequencers have become increasingly sophisticated during the past decade. They can run more samples, process them more quickly, and are easier to operate.