First, everyone knows that DNA resides in the nucleus of cells, but the real work of metabolism, including protein synthesis, takes place in the cytoplasm that is outside the nucleus. So everyone began looking for a molecular bridge between these two sites. They began looking for a transcribed copy of DNA . Go here to see what they found . And now to remind ourselves why everyone in the world knew that this transcribed information must be translated into protein.
Enzymes are the catalysts of the organic world.
Go here and have a look. Genetic information in the form of DNA is now protein information that will actually do the metabolic work of the cell. Count the amino acids in the protein and multiply by three. The enzyme tryptophan synthetase has 268 amino acids in it. The gene must be 804 base pairs long.