ABI 3730XL capillary-based DNA sequencer, used within the Human Genome Project at the Wellcome Sanger Institute, made by Applied Biosystems, 2002

ABI 3730XL a capillary-based DNA sequencer able to read 96 samples simultaneously, made by Applied Biosystems, United States, c.2002. One of a number of similar machines used within the Human Genome Project at the Wellcome Sanger Institute between 2002 and 2007.

The ABI 3730XL was a DNA sequencer released by an American Company, Applied Biosystems, in 2002. This machine was used at the Wellcome Sanger Institute between 2002 and 2007. It was used in the sequencing of the human genome as part of the Human Genome Project. The scale of the Human Genome Project required a large fleet of these machines, running continually.

This machine was part of the first generation of sequencing machines, using the technique of capillary electrophoresis to read fragments of DNA. It was designed to produce faster and cheaper sequences at higher volumes, with increased automation and the ability to read 96 samples across 96 capillaries simultaneously.

The machine uses long, thin, acrylic-fibre capillaries that with an electric current applied cause the DNA fragments to migrate and separate along them. DNA fragments are tagged with colours, one for each of the four nucleic bases of DNA (A, C, G, and T). A camera in the machine distinguishes each fluorescent molecule as they pass in front of the laser. This is recorded on a computer as a sequence or graph of different coloured peaks representing the bases that make up the DNA of the fragment.