Reading the Sequences

The sequence of nucleotides in a gene gives it meaning by storing the instructions for building the other molecules necessary for life. These instructions are read as a string of A’s, T’s, G’s, and C’s, such as ACGGTAACT. In the sense that there are 26 letters in the English alphabet, there are four letters in the alphabet of DNA.
The four letters in the DNA alphabet are actually abbreviations for the chemicals that make up the library of instructions.
A for Adenine
T for Thymine
G for Guanine
C for Cytosine