1. In the 1950 s, many scientists thought that proteins, not DNA, carried genetic information. Why did proteins seem better suited for storing genetic information? Biologists could already visualize proteins with electron microscopes, and so had an idea of how complex they were Proteins had more (20 amino acids) units than DNA did (4 nucleotides) Biologists knew that chromosomes were only comprised of proteins and not DNA DNA seemed too complex to carry information compared to more simple proteins.