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Discovery of DNA

Discovery of DNA


This section works from a perspective of the Nature of Science as you examine the scientists and their research that led to the discovery and identification of DNA as the material of heredity.  This tutorial will highlight the key discoveries that led to the identification of DNA as the molecule carrying the Genetic Code.  You will not be studying most of the people from 1960 onwards - although you will be learning the genetic processes that their research integrated.  You will finish with a look at the Human Genome Project.

To show a knowledge and understanding of the concepts involved in this research, you should be able to:

  1. describe the method and major results/conclusions of the work of
    • Griffith & Avery
    • Avery, Macleod & McCarty
    • Hershey and Chase
    • Chargaff
    • Rosalind Franklin
    • Watson & Crick
  2. describe how the experiments of the researchers stated in the first outcome have contributed to our understanding of genetics at the molecular level
  3. describe the contributions of Francis Collins, John Sulston and Craig Venter to the Human Genome Project.
  4. describe the Human Genome Project and the ethical dilemma that it generated among scientists.
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DNA Timeline

View this timeline first to get a sense of perspective on the discovery of DNA as the transforming molecule.

This tutorial will highlight the key discoveries that led to the identification of DNA as the molecule carrying the Genetic Code.  You will not be studying most of the people from 1960 onwards - although you will be learning the genetic processes that their research integrated.  You will finish with a look at the Human Genome Project.


Source: DNAi, Cold Spring Harbor Laboratory

Discovery of DNA as the Molecule of Inheritance

Hindsight is definitely 20-20. When we look back at the identification of DNA as the genetic material, and the search for its structure, we tend to highlight the key research studies that made major contributions to our understanding of these. However, it needs to be remembered that there was a huge amount of research, spread primarily over Europe and the US with no internet and poor telephone connections and two world wars. Politics and connections played major roles. James Watson, along with Francis Crick need to be acknowledged for his ability to select and pull the disparate bits of knowledge together to propose the structure of DNA in 1953. It is only fitting that the Human Genome Project's goal was to be completed in April 2003 - 50 years after Watson and Crick published their seminal paper.

Source: M. O'Mahony, open source images

Discovery of DNA

Part 2

Source: M. O'Mahony

Student Notes Template

Template for student notes for this tutorial.


Source: M. O'Mahony, Open Source images

The DNA Double Helix Discovery — HHMI BioInteractive Video

The discovery of the structure of the DNA double helix was one of the most important of the 20th century. In this educational video, explore Watson and Crick’s quest to understand DNA’s structure, and Rosalind Franklin’s key insights via x-ray crystallography.

Rarely seen archival footage is combined with interviews with some of today’s leading scientists to bring this Nobel Prize–winning discovery and all of its scientific implications to life.

Published on Aug 26, 2014

Source: HHMI Biointeractive YouTube Channel

The Talking Glossary of Genetic Terms

This web-based oral dictionary from the National Human Genome Research Institute has some UTS contributions:  

              Victor Ji (class of  ) contributed to the project as part of his Biology Portfolio.

and         Meg O'Mahony (member of the Education and Researcher review team).


Source: National Human Genome Research Institute

NOVA: Journey into DNA

This is the phenomenal program put together by NOVA (PBS)  called the Journey into DNA.

There are links to some wonderful interactive activities and the video series.

Source: NOVA (PBS)

Learn Genetics

This is one of the best sites about DNA science.  It is kept updated in terms of new issues and research. You will probably find it very useful for your research for your seminar!

Source: Learn Genetics, University of Utah Health Sciences

DNA from the Beginning

Cold Spring Harbor Laboratory has developed this interactive webpage to explore all of the key information.  This is good - but has a lot of additional resources including animations, videos and additional links.

While this is an excellent website, explore it more for interest to to pick up additional details on specific aspects of DNA discovery.  There is too much here to try to remember all of it.

Source: DNA from the Beginning, Cold Spring Harbor Laboratory

Nature: 50 Years from DNA

Nature, one of the most prestigious research journals, published a special edition to celebrate the 50 year anniversary of Watson & Crick's seminal paper on DNA structure and the "completion" of the Human Genome Project.  You can access it at

Source: Nature

DNA: The Double Helix game

On the Nobel Prize games site you can find the DNA: Double Helix game

Give it a try


Hershey & Chase Interactive

McGraw-Hill has developed an interactive page on Hershey and Chase's "Blender Experiment" which confirmed DNA as the molecule of heredity.

Source: McGraw-Hill

Levene's paper published in Journal of Biological Chemistry

Levene, P.A. 1919. The Structure of Yeast Nucleic Acid:IV. Ammonia Hydrolysis
J. Biol. Chem. 1919, 40:415-424.


Source: J. Biol. Chem

Chargaff's paper

Vischer, E. and Chargaff. E. 1948. The Separation and Quantitative Estimation of Purines and Pyrimidines in Minute Amounts J. Biol. Chem. 176: 703-714.


Source: J. Biological Chemistry

Hershey & Chase publication

Hershey, A. J. and Martha Chase. 1952. Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage* . JGP 36 (1): 39-56 doi: 10.1085/jgp.36.1.39

JGP: Journal General Physiology


Source: Journal General Physiology

Nature 1953. Watson & Crick's paper

Watson, J.D. and F. H. C. Crick. 1953. Molecular Structure of Nucleic Acids: A
Structure for Deoxyribose Nucleic Acid. Nature. 171 (4356):737-738.


Source: Nature

Rosalind Franklin's paper, same Nature journal as Watson & Crick

Franklin, R. and R. Gossling. 1953. Molecular Configuration in Sodium Thymonucleate. Nature. 171 (4358): 740-741.


Source: Nature

James Watson sells Nobel Prize Medal

James Watson sells his Nobel medal for $4.1 million

Source: NY Times, 4 Dec 2014