Skip to content

When you choose to publish with PLOS, your research makes an impact. Make your work accessible to all, without restrictions, and accelerate scientific discovery with options like preprints and published peer review that make your work more Open.


How to Use the Genetic Code for Passwords


Codons_aminoacids_tableNeed a password for a new device or service? Try the genetic code.

Messenger RNA triplets and the amino acids they specify provide nearly endless password possibilities. And it’s timely — the People’s Choice for Science magazine’s Breakthrough of the Year is “Giving Life a Bigger Genetic Alphabet.”

I began using the code for passwords years ago, when an IT-savvy friend setting up my clunky desktop computer told me a password should be:

• Alphanumeric
• More than 7 numbers or letters
• Obvious to me, but not to anyone else

The genetic code may seem like random gibberish to normal people, but can have meaning to biologists.

Francis Crick
Francis Crick

The genetic code is the correspondence between the 20 types of amino acids and the 61 types of messenger RNA triplets (codons, representing DNA) that specify them. The same codons spell the same amino acids to all organisms. The RNAs of humans, hydras, hippos, hydrangeas, Haemophilus influenzae, and even viruses follow the same rules. This “universality” is why human proteins are manufactured in bacterial cells, bacterial insecticides are produced in corn, and an Ebola vaccine is made in tobacco cells.

Francis Crick proposed genetic code words (codons) as part of his “adaptor hypothesis,” which Marshall Nirenberg and Heinrich Matthaei at the NIH demonstrated with brilliant experiments in 1960 and 1961. They challenged bacterial cells to make tiny proteins using simple RNA molecules. When UUU… led to a string of phenylalanines, for example, they had the first piece to the puzzle. Fed more complex RNAs, the bacteria revealed more code words.

Marshall Nirenberg
Marshall Nirenberg

Wrote Dr. Nirenberg in his research notebook, “we would not have to get polynucleotide synthesis very far to break the coding problem … we could crack life’s code!” …“we would not have to get polynucleotide synthesis very far to break the coding problem … we could crack life’s code!” And so they did.

Crick, George Gamow, and other luminaries of the DNA discovery era famously formed the “RNA tie club,” in which each discoverer of a codon assignment was honored with a tie festooned with a double helix. The club had two dozen members, representing the 20 amino acids and 4 RNA bases.

Here are a few ways that combinations of codons and the standard three-letter amino acid abbreviations can make great passwords. (And a link to a list of amino acid abbreviations for those who don’t remember Bio 101.)

Data from the genetic code experiments.
Data from the genetic code experiments.


UUUpheAAAlysCCCpro (the first 3 pieces to the puzzle)
UUUAUApheilu (the first co-polymer in the experiments)




Sulfur-containing: AUAmetUGUcys
Rings: CCUproline   UAUtyrosine
Simplest: GGUglycine   GCAalanine   AGCserine

SYNONYMOUS (amino acids corresponding to more than one codon)

Ehlers-Danlos syndrome: Arg134Cys
Huntington disease CAGglnx36HD
p53 oncogene UGAACAGUAp53
(Researchers should not use mutations they are working with. Someone will guess it.)

The genetic code is redundant — CCA and CCG both encode proline, for example – but passwords are not. Substitute the end G for the end A and your Amazon account won’t work.

gc posterPlan password choices, or have a chart of the genetic code in plain sight, as I do in my office. I got the poster after I had to change my Apple ID under time pressure, and I inadvertently typed in CAA for histidine, only to discover that I had specified glutamine.

Please send in other password suggestions!

Happy holidays and thanks for reading DNA Science!


Leave a Reply

Your email address will not be published. Required fields are marked *

Add your ORCID here. (e.g. 0000-0002-7299-680X)

Back to top