DNA Analyzer 3730xl

With a daily production capacity of over one million nucleotides, the DNA Analyzer 3730xl has been highly sought after for large-scale sequencing projects since its release in 2002 by Applied Biosystems. We were the first in Canada to acquire this instrument in the same year. All sequencing projects on our platform are conducted using this device.

The instrument is composed of 96 capillaries, an electrophoresis system, a laser, and a CCD camera. The capillaries, with a diameter of approximately 250 µm, are filled with a polymer that acts as a molecular sieve. DNA molecules are electro-injected into one end of the capillaries and then migrate throughout them under the influence of a very high voltage (8,500 volts), separating them based on their length. Near the anode, a laser beam passes through each capillary to excite the fluorescent molecules that have been incorporated into the DNA during the sequencing reaction. A CCD camera collects the emitted light from the fluorescent molecules as they pass in front of the laser beam. Since each of the four nucleic bases (A, C, G, and T) is associated with a specific fluorochrome, the system can distinguish them from each other based on the emitted wavelength. The instrument is connected to a computer that continuously records the signals and analyzes them once the migration is complete. Following the base calling for each of the 96 samples, data files are generated.

The sequencing method used is Sanger sequencing, which utilizes the random termination of DNA elongation using the four ddNTPs labeled with a fluorochrome.