Automated DNA sequencing utilizes a fluorescent dye to label the
instead of a radioactive isotope. The fluorescent dye is not an
hazardous chemical and has no special handling or disposal
of using X-ray film to read the sequence, a laser is used to stimulate
fluorescent dye. The fluorescent emissions are collected on a charge
device that is able to determine he wavelength. The Perkin-Elmer
Biosystems (ABI) DNA sequencers are designed to discriminate all four
fluorescent dye wavelengths simultaneously, which allows for complete
sequencing in one lane on the gel.
Varying degrees of automation are also available. For full automation, all that is required is to load a sample tray with template DNA; the equipment performs the labeling and analysis. The other option is to perform the labeling reactions with fluorescent dyes, load the samples onto a gel, and place the gel into the DNA sequencer. The equipment performs the separation and analysis. The system automatically identifies the nucleotide sequence and saves the information on the computer. Thus, only a review of the data is necessary to ensure no anomalies were misidentified by the computer.
The greatest obstacle to researchers when converting from manual to automatic DNA sequencing is being required to learn the use of computer software necessary to interpret the results.
Automated DNA sequencing equipment can eliminate the need for radioactive isotopes to label DNA, thereby reducing the volume of low-level radioactive waste generated on campus. As a general approximation, one template of manual DNA sequencing will produce 83 mL of liquid waste and 0.167 gallon of solid waste. As a result, every 45 templates processed by automated DNA sequencing reduces the amount of manual DNA sequencing. The time saved is due to not having to perform autoradiography or associated tasks required for working with radioactive materials such as radiation surveys, inventory/disposal documentation, etc. Finally, automated DNA sequencing provides more reliable research results than manual DNA sequencing, thus maintaining the integrity of the research.