The astronomical length of DNA

Just how long is all of your DNA?

Let’s start with a quick recap. The sequence of Deoxyribonucleic acid (DNA), is famously spelt out in just 4 letters — A T G and C. Each letter represent the repeating ‘bases’; adenine, thymine, guanine and cytosine. And the famous DNA double helix is a twisted ladder, each rung made from a pair of bases. Adenine always pairs with thymine whilst cytosine pairs with guanine.