2. Genomics

2.2. DNA Sequencing

DNA sequencing is a process  used to find out the exact order of bases in a strand of DNA. For many years, a technique called capillary electrophoresis (CE) DNA sequencing (or Sanger sequencing) was used in laboratories all over the world.

The human genome has about 3 billion (3.000 million) base pairs. To sequence the first full human genome took over 10 years and the first draft was published in 2001.

Follow this link to see a video which illustrates the principle of the Sanger method of DNA sequencing:

Source: http://www.dnalc.org/view/15479-Sanger-method-of-DNA-sequencing-3D-animation-with-narration.html

A new method has been found since the first human genome was sequenced. This is called next generation sequencing (NGS). This process is a lot faster and has allowed much more rapid research progress. The basic chemistry is the same as for Sanger sequencing. However the technique allows millions of tiny fragments of DNA to be sequenced at the same time, rather than just a few hundred.