How did scientists discover the structure of genetic material by exploiting the kitchen blender?

Through successive years, researchers have tried to discover the main component of genetic material; Until scientists Alfred Hershey and Martha Chase were able to prove that genes contain DNA and not proteins.

70 years ago, on September 20, 1952, the results of one of the most important experiments in the history of modern biology, the Waring blender experiment, also known as the Hershey-Chase experiment, were published.

During that experiment, researchers Alfred Hershey and Martha Chase sought to resolve the common dispute during that period regarding the nature of genes (genetic material) and answer the question: Is “DNA” (DNA) responsible for transmitting genetic traits from one generation to another, or does that role lie? On the proteins?

As a result of his numerous contributions to revealing the properties of the genetic material of viruses, geneticist Hershey was awarded the Nobel Prize in "Physiology or Medicine" in 1969, in partnership with scientists Max Delbrück and Salvador Luria.

Differing beliefs about the nature of genes

Genes play several important roles, including controlling the growth of different organisms by working to direct the body to manufacture proteins with multiple functions. It also has the role of transmitting physical and vital genetic traits between successive generations.

In 1900, researchers were able to determine the chemical structure of DNA, and proved that DNA is an essential component of cells, but many scientists believed that genes are made of proteins, not DNA.

And the hypothesis of the scientist Phipps Levine, a researcher at the Rockefeller Institute for Medical Research in New York City, called the " Tetranucleotide hypothesis", supported that belief. It is the hypothesis that indicated that DNA possesses a limited number of building units, which means that it does not have the sufficient flexibility required to carry many genetic traits, unlike proteins that have more building units.

Initiation of linkage between DNA and genetic material

In 1928, the scientist Frederick Griffiths conducted several experiments on two types of pneumococcal bacteria, during which he observed a unique phenomenon specific to bacteria and called the "transformation principle".

During the experiments, Griffith noticed the transformation of bacterial cells from the non-toxic type to the poisonous type by combining the two types of bacteria, which means the transfer of genetic material between them, but he could not determine what that substance was.

Subsequently, researcher Osald Avery supported this rule in 1944, and his colleagues proved that the genetic material that is transferred from one bacterium to another includes parts of its DNA, which laid the foundation for adopting the hypothesis that genes contain DNA.

Waring's blender experiment settles controversy

Alfred Hershey and Martha Chase published their research paper in 1952 after conducting several experiments to determine the material component of the genes, and the experiments depended on the use of the "Bacteriophage T-2" virus, which is one of the viruses that infect E-coli. ) and cause her death.

The researchers found that the virus infects bacteria by attaching to its outer membrane and then injecting it with genetic material in order to reproduce inside it. To determine the type of material injected into the bacteria, the researchers used the technique of "radioactive isotope labeling", which means injecting a radioactive substance into both the viral protein and its DNA in order to track them.

After the bacteria were infected with the radioactive virus, the two scientists used the Waring blender to destroy the bacteria and separate its components by spinning the blender, in a procedure similar to centrifugal technology. The Waring blender is a traditional device used in the kitchen for the purposes of preparing food and drinks.

By analyzing the separated components, the researchers found that the radioactive DNA was the material transferred inside the bacteria, not the protein, which finally settled the controversy over the components of genes.

Research continued during the following years that contributed to the development of our concept of the role and structure of DNA, the most famous of which is the discovery by Watson and Crick of the structure of the double helix structure of DNA in 1953, and the discovery of the 46 chromosomes found in human cells in 1955.