What is an FNA File?

How to Open, Edit, & Convert FNA Files

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A file with the FNA file extension is a FASTA Format DNA and Protein Sequence Alignment file that stores DNA information that can be used by molecular biology software.

FNA files, specifically, may be used to hold just nucleic acid information while other FASTA formats contain other DNA-related information, such as those with the FASTA, FAS, FA, MPFA, SEQ, NET, or AA file extensions.

These text-based FASTA formats originally arose out of a software package with the same name, but are now used as a standard in DNA and protein sequence alignment applications.

How To Open an FNA File

FNA files can be opened on the Windows, Mac, and Linux operating systems with Geneious through its File > Import > From File... menu.

You might also be able to open FNA files with BLAST Ring Image Generator (BRIG).

If these programs aren't opening your FNA file, you might check to see if you're misreading the file extension. Some files, like FNG (Font Navigator Group) files, look similar to FNA files but are used for entirely different formats and so of course aren't opened in the same way.

Tip: Try opening your FNA file with Notepad++ or another text editor if the program ideas above aren't working out. Your specific FNA file may have nothing to do with the FASTA format, in which case opening the file as a text document may reveal text that identifies what was used to create the file or what format the file is in.

If you find that an application on your PC does try to open the FNA file but it's the wrong application or if you would rather have another installed program open FNA files, see my How To Change the Default Program for a Specific File Extension guide for making that change in Windows.

How To Convert an FNA File

I can't verify this since I haven't tried it myself, but you should be able to use Geneious to convert an FNA file to lots of other formats, like FASTA, GB, GENEIOUS, MEG, ACE, CSV, NEX, PHY, SAM, TSV, and VCF. This can be done through Geneious' File > Export menu.

Geneious should also be able to convert the FNA file to an image file in the PNG, JPG, EPS, or PDF format via the File > Save As Image File... option.

Although you can't normally just rename a file's extension to something else and expect it to work in the same manner, you can rename an .FNA file to an .FA file if your particular DNA sequencing software will only recognize the FA format.

Note: Instead of renaming file extensions, you'll want to use a free file converter to convert other file types. In the case with FNA and FA files, it just so happens that some programs will only open files that have the FA file extension, in which case renaming it should work fine.

More Help with FNA Files

See Get More Help for information about contacting me on social networks or via email, posting on tech support forums, and more.

Let me know what kinds of problems you're having with opening or using the FNA file and what programs you've already tried and then I'll see what I can do to help.