New optical design for automated DNA sequencer

A second generation optical design for the ABI PRISMTM 377 DNA sequencer enhances sensitivity and increases sequencing throughput by taking advantage of simultaneous four color detection using a spectrograph and CCD array. On-axis laser illumination using a small turning mirror to excite sample fluorescence replaces the Brewster's angle geometry of the first generation sequencer. The small turning mirror blocks direct reflection of laser light from the collection path. Alignment precision and mechanical stability must be sufficient to avoid image wander on the spectrograph slit which would add noise. The spectrograph slit is underfilled to maximize signal strength and reduce mechanical vibration sensitivity. The primary noise sources have been identified and minimized such that the instrument is shot noise limited. The instrument may be reconfigured through software for use of additional or different fluorescent dye labels as required by new genetic analysis applications. The overall result is a flexible instrument platform with increased throughput, improved sensitivity and longer sequences read.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.