Файл FASTA

The .fasta format belongs to the category of bioinformatics data files. Contents of .fasta files include sequences of genetic data - they can contain information about the structure of DNA and RNA, but also about protein structures. The content is organized in a layout specific to this standard. One of its characteristic features is a > header line (called a defline), in which an identifier and descriptive annotations can also be recorded. One or more lines of raw sequence letters follow each header, using IUPAC nucleotide or amino-acid codes.

.fasta files can store a large number of sequences in a single file, which is why multi-.fasta files are often used as reference databases. All this information is used by specialized programs for genetic analyses. Thanks to the .fasta format, DNA comparative tests can be performed, as well as studies on the evolution of genetic structures.

Because .fasta stores only the identifier and raw sequence - without quality scores or rich annotations - complementary formats are often used alongside it: .fastq files add per-base quality scores for sequencing reads, while GenBank files carry full feature annotations. The format was developed by William R. Pearson and David J. Lipman for their FASTA sequence-comparison program and has since become the baseline plain-text standard for sharing biological sequences across tools and databases worldwide.

Common variant extensions include .fa, .fna (nucleotide sequences), .faa (amino-acid sequences), and .ffn (coding sequences).