ab1

AB1 is a file format most commonly associated with Applied Biosystems DNA sequencing instruments for storing Sanger sequencing chromatogram data. The AB1 extension designates a binary container that holds the electropherogram traces for the four nucleotide dyes, the base-called sequence, and run-related metadata. The format originated with ABI instruments such as the 3730 and has been encountered in both legacy data and newer projects that still generate AB1 outputs.

Software compatibility and usage: AB1 files can be opened by various software applications including Chromas, FinchTV, SnapGene Viewer, and several lab informatics suites. In bioinformatics, many tools can read AB1 files and extract sequence and quality information, enabling conversion to FASTA or FASTQ formats or direct import into analysis pipelines. Biopython’s SeqIO module, for example, supports AB1 parsing. Because AB1 is a proprietary format with vendor-specific variations, users may encounter differences between instrument models and software versions; converting to open formats is common to ensure long-term accessibility. AB1 data is typically used for sequence verification, primer validation, and trace-level analysis of Sanger reads. Best practices emphasize accompanying AB1 files with metadata (sample identifiers, run date, instrument, primer sequences) to maintain traceability.

Context and note: In addition to the sequencing context, the acronym AB1 may appear in other domains, but within genomics it is most widely recognized as the chromogram file format with extension .ab1.