Worked example 2 — identify the nucleic acid

A nucleic acid is analysed: A = 12%, U = 18%, G = 39%, C = 31%. It contains uracil, so it is RNA; A ≠ U and G ≠ C, so it is single-stranded (as RNA normally is). If a sample had A = 20, T = 20, G = 30, C = 30, it would be double-stranded DNA.