What Is an FNA File?

How to open, edit, and convert FNA files

What to Know

  • An FNA file is a FASTA Format DNA and Protein Sequence Alignment file.
  • Open one with Geneious.
  • Convert to FASTA and similar formats with that same program.

This article explains what an FNA file is, how to open one, and how to save one to a different format like FASTA, GB, VCF, images, etc.

What Is an FNA File?

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, FFN, FAA, FRN, 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.

FNA files in Windows 10
FNA Files.

FNA also refers to some technology terms that have nothing to do with this file format, like ​final network acceptance, file name/attribute augmentation facility, Fujitsu network architecture, and fast neighbor advertisement.

How to Open an FNA File

Open one in Windows, macOS, and Linux with Geneious (it's free for 14 days). To do this, navigate to the File > Import menu and choose to import the file via the From File menu item.

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

Try Notepad++ or another text editor if those ideas aren't working out. The file might indeed be text-based and simple to read, or you might find that it has 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.

How to Convert an FNA File

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

That same program should also be able to save the file to PNG, JPG, EPS, or PDF, via File > Save As Image File.

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 a .FNA file to a .FA file if your particular DNA sequencing software will only recognize the FA format.

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.

Still Can't Open It?

If after using the programs from above, you still can't get your file to open, you might find that the file extension doesn't actually read .FNA but instead something that just looks similar.

For example, FNG (Font Navigator Group) files look an awful lot like they say ".FNA" but if you look closely, only the first two letters are the same. Since the file extensions are different, it's an indication that they're of a different file format and will most likely not work with the same programs.

The same could be said for many other file extensions like FAX, FAS (Compiled Fast-Load AutoLISP), FAT, FNTA (Aleph One Font), FNC (Vue Functions), and FND (Windows Saved Search).

The idea here is to just make sure the file extension reads .FNA. If it does, try again to use the programs from above to open or convert it. If you have a different kind of file, research its extension to find out which applications are needed to open or convert it.

  • How do you open an FNA file in Python?

    First, convert the FNA file to FASTA format using a third-party application such as Geneious. Then, you can download Biopython, a set of freely available tools for biological computation for work in bioinformatics. Finally, refer to the Biopython Tutorial and Cookbook for instructions on working with FASTA files.

  • How do I find my FNA maker numbers on an Ancestry raw file?

    You can download most DNA data from Ancestry.com in .txt format. However, only customers whose DNA was analyzed with next-generation sequencing (NGS) have the option to download a VCF file. To download a VCF file, you must be the DNA owner, have DNA tested using NGS technology, and have at least 350 MB of space available on your device.

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