[6] He has made significant scientific contributions in virus biology, X-ray, neutron and electron diffraction, and protein plasticity.
While waiting for his degree he worked under Max Delbrück at the California Institute of Technology as post doctoral student.
In 1956 he and Franklin published individual but complementary papers in the March 10 issue of Nature, together showing that TMV was a hollow rod, rather than a solid structure as generally believed.
[12] Caspar-Klug theory has played an important part in shaping the subsequent study of viruses and other macromolecular assemblies.
The original concept was based mainly on electron microscope studies, and has now been refined to take account of the atomic resolution structure of viruses, and other details of protein–protein interactions that crystallography has elucidated.