Hershey–Chase experiment (1952)हर्शे–चेज़ प्रयोग (1952)
NCERT Fig 5.5 · Class 12 Biology · Chapter 5 · interactive diagram
Parts and their functions
- Radioactive phages (रेडियोधर्मी फ़ेज) — ³²P labels DNA (DNA has P); ³⁵S labels protein coat (protein has S).
- Infection of E. coli (ई. कोलाई का संक्रमण) — Phages attach to bacteria and inject their genetic material.
- Blending and centrifugation (ब्लेंडिंग और अपकेंद्रण) — Blender removes viral coats; centrifuge separates bacteria (pellet) from phage particles (liquid).
- ³²P: bacteria radioactive (³²P: जीवाणु रेडियोधर्मी) — Radioactive DNA went into the bacteria.
- ³⁵S: bacteria not radioactive (³⁵S: जीवाणु रेडियोधर्मी नहीं) — Protein did not enter the bacteria; the label stayed outside with the coats.
Steps
- Label phages: ³²P (DNA) or ³⁵S (protein).
- Phages infect E. coli.
- Blend and centrifuge.
- Only ³²P ends up inside bacteria: DNA is the genetic material.
Original diagram drawn by Simple Learning Hub, based on NCERT Fig 5.5. Report a mistake