Zufällig war Glenn Millikan, ein Freund Bernals, gerade in einem Forschungslabor in Uppsala, wo man große Pepsinkristalle zur Verfügung hatte. Er brachte einige dieser Kristalle noch in der Mutterlauge mit nach Cambridge.
A friend of Bernal's named Glenn Millikan had happened to visit a lab in Uppsala, Sweden, where large pepsin crystals had been obtained, and he brought some of the crystals, still in their mother-liquor, back to Cambridge.