Previous attempts at DNA storage have encoded data in the genetic code, but an alternative approach just uses a series of tiny holes
Source:
https://www.newscientist.com/article/2208036-gettysburg-address-stored-in-dna-using-a-binary-code-made-of-holes/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home