What is MIME type "chemical/seq-na-fasta"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The MIME type chemical/seq-na-fasta represents nucleotide sequences in a FASTA text format.
It uses a plain text structure with a header line starting with a ">" symbol, followed by lines of sequence data.
This format is key in storing DNA or RNA sequence information.
Common file extensions include FASTA and FA.

Main use: Storing nucleotide sequences.
Use case: Bioinformatics research and genomic analysis.
Key fact: Files are simple text and can be opened with any text editor.
Usage: Supported by many sequence analysis tools and databases.

For further details on the format, see the FASTA format article.

Associated file extensions

.fasta, .fa

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: chemical/seq-na-fasta

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="chemical/seq-na-fasta">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');
    
    http.createServer((req, res) => {
      res.setHeader('Content-Type', 'chemical/seq-na-fasta');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.fasta, .fa

FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.