In 1953, Francis Crick and James Watson discovered structure of DNA and proved every human cell contains DNA and showed how it passed on information to parents to children.
Crick and Watson built on their knowledge in other types of science such as biochemistry. (With the help of new equipment.)
Crick had help from others like MauriceWilkins , an exert in x-ray photography and RosaslindFranklin who discovered how to take photographs of DNA.
2 Improvement in tech to help take first photo of DNA:
Electron Microscope
Computers
Discovering DNA couldn't be done without computers. Information carried in human DNA would fill up to 80,000 books but size of buying one electronic equivalent can be passed around the world instantly.
Crick and Watson's research was expensive as it required complex equipment and amount of skilled people. Most of the money came from the government. (Industries also contributed.)
Research was complex, so it needed scientists from 18 countries like USA, Britain, Japan, France, Canada to work on different parts of DNA.