DP1 Hershey and Chase and Chargaff's data HL

HL only

What did Hershey-Chase experiment determine?

it determined that DNA is the genetic material, not protein.

Process of Hershey-Chase experiment

Scientists used viruses bacteriophages, that infect bacteria, for the experiment. They used phosphorus to label the DNA of the viruses, as phosphorus is found in DNA but not in protein. They used sulfur to label protein in the viruses, as sulfur is found in protein but not in DNA. Then, scientists allowed the viruses to infect the bacteria. They found that only the radioactive DNA entered the bacterial cells, while the radioactive protein stayed outside. This showed that DNA carries the genetic information necessary to produce new viruses, not protein.

What did Chargaff’s data analysis determine?

it determined that DNA has a double-stranded structure and it also gave us clues about complementary base pairing.

Process of Chargaff’s data analysis

He used paper chromatography to separate the components of the DNA and measure the relative concentrations of A, T, G, and C bases in them. He concluded that the amount of T was equal to the amount of A, and amount of G was equal to the amount of C.