FASTA format is a simple text format used in bioinformatics to store DNA, RNA, or protein sequences. Each entry starts with a header line beginning with > followed by one or more lines of sequence using single-letter codes.

Quick Scoop

A typical FASTA entry looks like this:

text

>sequence_name optional description
ATGCGTACGTTAGC

Key Points

  • The first line is the header or description line and begins with >.
  • The following lines contain the biological sequence itself.
  • A single file can contain multiple sequences ; that is often called multi-FASTA.
  • FASTA is widely used for sharing and analyzing sequence data in bioinformatics.

Why It Matters

FASTA is popular because it is easy to read, easy to generate, and widely supported by bioinformatics tools. It is a standard way to exchange reference genomes and other sequence collections.

Example

text

>human_gene_1
ATGAAACTGCTGCTGAA
>mouse_gene_1
ATGCCCTGATTTGCAA

TL;DR

FASTA format is a plain-text way to store biological sequences, with a > header line and the sequence below it.