Sequencing employs a technique known as electrophoresis to separate pieces of DNA that differ in length by only one base. ... Smaller molecules move through the gel more rapidly, so the DNA molecules become separated into different bands according to their size.

What is the process of DNA sequencing?

DNA sequencing is the process of determining the sequence of nucleotides (As, Ts, Cs, and Gs) in a piece of DNA. In Sanger sequencing, the target DNA is copied many times, making fragments of different lengths.

How do automated DNA sequencers work?

In an automatic DNA sequencer, just as in any DNA sequencer, the DNA is injected into the gel wells at the top of the tank, and a negative charge is applied to that end of the tank. The negative charge provides a strong impetus for the DNA strands to travel different distances, to the end of the tank.