Study notes for the main scientists that participated in the early discovery of DNA and the early studies about DNA

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-Hershey and Chase showed that DNA is the hereditary material of phages

-Hershey and Chase labeled protein in a T2 phage with a radioactive tag

-Then they labeled DNA in a separate batch of phage with a radioactive isotope

-Both batches of tagged phages were allowed to infect separate batches of E.Coli bacteria

-Afterwards, both sets of E. Coli. were placed in separate blenders to shake loose any parts of the phages that remained outside the bacterial cells

-The mixtures were then place in separate centrifuges and spun around to force the bacterial cells to form a pellet at the bottom of the centrifuge

-The viruses and parts of viruses remained in the supernatant

-Hershey and Chase found that the radioactively labeled proteins were found in the supernatant which contained viral particles

-Protein of the phage didn't enter the bacteria

-Bacteria infected with tagged DNA contained radioactivity

-Showed that DNA of the virus is injected into host cell and cause the bacteria to make new viral DNA and proteins

-DNA is hereditary material

-Griffith used two varieties of a bacterium

-One was harmless and other was pathogenic

-Griffith's experiment

-He inject a mouse with a pathogenic strain and it died

-Then he injected a mouse with a harmless strain and it lived

-Then he injected the mouse with cell remains of heat killed pathogenic strain and it lived

-Then he killed the pathogenic bacteria with heat and mixed the cell remains with living bacteria of the harmless strain and injected it into a mouse

-The mouse died and he found that some of the living cells were converted to the pathogenic form

-Experiment showed that some chemical substance caused the change of the living nonpathogenic substances into pathogenic substances

-Griffith called this change of the harmless DNA...