The ABI Prism�377 DNA sequencer is an automated system used to accurately determine the base sequence or size of DNA fragments. Fluorescently labeled DNA samples are loaded onto very thin vertical polyacrylamide slab gels and separated by electrophoresis. A laser beam continuously scans across the lower portion of the gel detecting up to four different fluorescent emissions simultaneously. Up to 96 lanes can be analysed on one gel. There are two software applications available for analysing the raw data:
Sequencing Analysis software is used for sequence data, which incorporates four different dyes to identify the A, C, G, T extension reactions. The software detects the peaks and determines the sequence. One-lane sequencing eliminates electrophoresis variables and reduces the signal to a consistent pattern allowing the computer to efficiently interpret the data.
Click 
for an image of a sequencing gel (100KB)
GeneScan Analysis software automates the process of separating, quantifying and sizing DNA fragments. An internal size standard within each lane ensures consistent and accurate fragment assignment, meaning that PCR products, such as STRs (Short Tandem Repeats) analysis, and AFLP (Amplified Fragment Length Polymorphism) fingerprinting, can be analysed faster and with a higher resolution than traditional methods.
Click for an image of a GeneScan gel (100KB)