"The DNA Story." 1973. Created by VSM Productions. Produced by Ronald Fouracre and Peter Shaw. Distributed
by John Wiley & Sons, London, New York.
Discovering the Base Pairs. (1:04)
James Watson: At that stage, they still hadn't completed the metal models of the bases that we
wanted, so I had cut out some paper models of the bases - not very accurate, but enough
so I could put hydrogen atoms on different places to see where you might form hydrogen
bonds. Francis said that I should definitely think about Chargaff's rules, that adenine
equals thymine and that guanine equals cytosine.
The next morning - I don't know why I didn't do it right away - it was a beautiful
spring, and the next morning I started playing with models, and I discovered that
you could put adenine and thymine together in the exact same way that you could put
guanine and cytosine together. That was sort of the base pairs. I was immensely excited.
Francis came in and got a point that I hadn't gotten at all; that you could flip the
pair so that adenine could be on either side of the thymine pair.
Creator: James D. Watson Associated: Francis Crick, Erwin Chargaff Clip ID: 1973v.3-models
Creator: VSM Productions, Ronald Fouracre, Peter Shaw Associated: Linus Pauling, Francis Crick, James D. Watson, Maurice Wilkins