Tutorial on base pairing

Even when the predominant tautomers for A, C, T and G are known there still are numerous base pairing combinations possible, and many of these non Watson-Crick base pairs appear in other nucleic acid structures.  Download the tutorial below on base pairing to build 2D models of the nucleotides and explore the many ways that they can base pair.  

To see the original full paper on the structure elucidation of B DNA by Watson and Crick see:  Link to paper