For a science fair project, two students decided to repeat the hershey and chase experiment, with modifications. they decided to label the nitrogen of the dna, rather than the phosphate. they reasoned that each nucleotide has only one phosphate and two to five nitrogens. thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. why won't this experiment work?

The experiment wont work because both DNA and Protein contain nitrogen in their structure.

Explanation:

DNA and protein both contain nitrogen but phosphate group is present in DNA but absent in Protein.So when those 2 students tried to lebel the nitrogen of DNA it can be possible that nitrogen of protein molecule is being lebelled rather than the nitrogen of DNA.

          As a result those 2 students do not found any trace of  nitrogen of  phage DNA inside the host Bacterium because the lebelled protein of the capsid remains outside the bacterium in form of ghost.