What the work claims
DNA, not protein, is the genetic material. This claim rests on differential entry and inheritance of radioactively labelled molecules during phage infection.
How it was done
Hershey and Chase used radioactive phosphorus-32 to label DNA and sulfur-35 to label protein in T2 bacteriophages. They infected bacteria, then separated phage coats from cells using a blender and centrifugation.
What holds up
The core result holds: most 32P entered bacteria and appeared in progeny; nearly all 35S stayed outside. The method isolated physical location and inheritance of labels. The conclusion — DNA, not protein, is the genetic material — follows directly from these observations.
What does not
It does not show how DNA encodes information, replicates, or mutates. It does not rule out all non-protein genetic roles for other molecules. It does not address RNA, epigenetics, or horizontal gene transfer.
Why it matters beyond the lab
It ended the protein-as-genetic-material consensus. It redirected molecular biology toward nucleic acids — enabling sequencing, recombinant DNA, and modern genetics. It established that heredity is a chemical process traceable by atomic labelling.
Is it worth your time
Yes. It is the cleanest experimental demonstration that DNA carries hereditary information — not as inference or correlation, but via direct tracking of labelled molecules across infection and replication.
