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Discovery of Equality in Nucleotides
Erwin Chargaff shows there are equal amounts of the nucleotides adenine and thymine (known as A and T) as well as equal amounts of guanine and cytosine (known as G and C) in every DNA strand, -
Proof that DNA Mediates Heredity
Martha Chase and Alfred Hershey demonstrate that not viral protein and viral DNA direct the reproduction of new viruses, thus confirming that DNA is the molecule that mediates heredity. -
Wilkins and Franklin X-Ray DNA
Maurice Wilkins and Rosalind Franklin take X-ray's of DNA crystals which later leads Watson and Crick toward their famous conclusions. -
DNA Structure Discovered
James Watson and Francis Crick describe the 3D structure of DNA as a double helix: two spiraling strands held together by complimentary base pairs (such as Adenine and Thymine or Cytosine and Guanine). -
Discovery that Extra Chromosome Causes Down's Syndrome
A total of three copies of chromosome 21 causes Down's syndrome as determined by Jerome Lejeune. -
Genetic Code Cracked
Francis Crick, H. Gobind Khorana, Marshall Nirenberg, George Gamow, and other scientists crack the genetic code -- 64 nucleotide triplets that make up a universal genetic code for all cells and viruses. -
Restriction Enzymes Isolated
Werner Arber isolates restriction enzymes in DNA. -
Paul Berg Creates First Recombinant DNA Strand
Building upon the work of a Stanford graduate student and his faculty advisor, Paul Berg uses restriction enzymes to splice DNA, thus creating the first strand of recombinant DNA. -
Sequencing of DNA Occurs
Fred Sanger and other scientists sequence a strand of DNA. -
First DNA Genome Sequenced
The first complete DNA genome to be sequenced is bacteriophage φX174 -
PCR is Developed
Kary Mullis developes the Polymerase Chain Reaction, used to date the most accurate and sensitive methods for amplifying DNA. -
First Automated Sequencing Machine Produced
Applied Biosystems markets the first automated sequencing machine, the model ABI 370. -
First Published Complete Genome
Craig Venter, Hamilton Smith, and colleagues at The Institute for Genomic Research (TIGR) publish the first complete genome of a living organism, Haemophilus influenzae, a bacterium. Its publication in the Journal Science marks the first use of whole-genome shotgun sequencing, consequently eliminating the necessity of the initial mapping efforts. -
1st Draft of the Human Genome
A draft sequence of the human genome is published.
