Since the 1970’s, when researchers first sequenced DNA using laborious and time consuming methods, DNA sequencing has become automated and considerably faster. The Human Genome Project, for example, which began in 1990 and involved thousands of scientists worldwide to map the estimated 25,000 genes of the human took over 10 years to complete. Now, such procedures can take just a matter of days and even hours.
The fastest method for high volume sequencing uses fluorescent dyes to label the four base pairs each of which emits at a different wavelength when illuminated by a light source, such as a laser. By chemically terminating the DNA strand systematically along its length (with a resolution of a single base pair) and tagging the end of each fragment length with a fluorescent label, the chain-terminating base nucleotides can be identified using an excitation source in a high-throughput automated sequencing process.
Laser light is used as the monochromatic light to selectively excite the fluorescent dyes. More than anything, power, stability and reliability are key as these factors determine the speed of analysis, the accuracy of the data and the cost of each sequence.
Laser Quantum recommend the gem family of lasers as they are small, powerful and very reliable under heavy usage and over long time periods.