When describing the helical structure, Watson and Crick (1953a) point out that the chains take a right handed helical arrangement. Interestingly, the chains run opposite to each other. With regards to the details of each chain, Watson and Crick (1953a) suggest that they consist of a base and a phosphate. The base is on the inner part of the helix, whereas the phosphates are located on the outer part of the same.
Based on their description of the DNA structure, the two biologists are able to make further predictions. One of their predictions is drawn from the fact that the DNA structure is an open one (Watson & Crick, 1953a). In addition, the two biologists point out that such a structure is usually characterized by high water content. Based on this, the scholars predicted that whenever water content is low, the bases would tilt. The tilting will make the structure more compact.