Linus Pauling and Robert Corey's Expirements (23h 53min, mar 1, 1951 y – 14h 49min, may 31, 1951 y)
Description:
 They used X-ray crystallography on crystalline peptides to research DNA and its structure. 
Added to timeline:
Date:
23h 53min, mar 1, 1951 y
14h 49min, may 31, 1951 y
 ~ 3 months