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S Dear

Publications and source records attributed to S Dear.

3 recordsLinked to original sources

Indexing the sequence libraries: software providing a common indexing system for all the standard sequence libraries.

We describe a set of programs for creating and using indexes for the distributed forms of the major sequence libraries. The indexes conform to the specification of those distributed on cd-rom by the EMBL sequence library. The programs create entry name, accession number, author and freetext indexes and a brief directory index. If a suitable application program is given an entry name or accession number these indexes allow rapid retrieval of sequences or annotation. Similarly the author and freetext indexes provide the data for extremely fast searching on author names and "keywords". The indexing programs can create indexes for EMBL, Swiss-Prot, GenBANK, PIR and NRL3d libraries. We also describe the organisation and use of the different sequence libraries and their index files.

Abstracting and Indexing

A standard file format for data from DNA sequencing instruments.

There are now a number of machines for determining DNA sequences. These devices are currently of two types: those such as the Applied Biosystems 373A and the Pharmacia A.L.F. which interpret the sequences of samples as they run on gels within the machine, and those, such as the Bio-Rad and Amersham readers that scan and analyse conventional autoradiographs. Both types of machine can produce their data in the form of traces which represent the band intensity of each of the four base types at each position in the sequence. At present all the machines write files in different formats. We describe a machine independent format for storing data derived from automatic sequencing machines. Files in this format can store the derived sequence, the traces and a set of confidence measures for each base. We have adopted the format as the standard for our sequence handling software.

Databases, Factual

A sequence assembly and editing program for efficient management of large projects.

We describe a sequence assembly and editing program for managing large and small projects. It is being used to sequence complete cosmids and has substantially reduced the time taken to process the data. In addition to handling conventionally derived sequences it can use data obtained from Applied Biosystems,Inc. 373A and Pharmacia A.L.F. fluorescent sequencing machines. Readings are assembled automatically. All editing is performed using a mouse operated contig editor that displays aligned sequences and their traces together on the screen. The editor, which can be used on single contigs or for joining contigs, permits rapid movement along the aligned sequences. Insertions, deletions and replacements can be made in individual aligned readings and global changes can be made by editing the consensus. All changes are recorded. A click on a mouse button will display the traces covering the current cursor position, hence allowing quick resolution of problems. Another function automatically moves the cursor to the next unresolved character. The editor also provides facilities for annotating the sequences. Typical annotations include flagging the positions of primers used for walking, or for marking sites, such as compressions, that have caused problems during sequencing. Graphical displays aid the assessment of progress.

Base Sequence