Experimental Cell Biology

Question 1

Describe the experiment undertaken by Avery et al. to prove that it is DNA that carries the information?

Answer 1

They mutated pathogenic smooth strain bacteria into non-pathogenic rough stain bacteria but when they put them in the presence of the cell contents from smooth strain they transform back to smooth strain showing something must be present to transform it. Avery et. al then put rough strain in with, RNA, protein, DNA, lipid and carbohydrates seperately and the only one that transformed back to smooth strain what the one with DNA shows the information is stored in it.

Question 2

Describe the experiment undertaken by Hershey and Chase in order to prove there is heritable information?

Answer 2

They used a T2 bacteriophage with targets E-coli cells, once they had attached to the E-coli the bodies were blended off. They then looked for what had been transferred by tagging the protein coat in the bacteriophage with 35S and the DNA with 32P - only the DNA shows labelled