Extraction, purification and properties of aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea

Isolated and purified the light-emitting protein from the jellyfish Aequorea, characterising its behaviour and noting alongside it a second protein that fluoresced green under ultraviolet light.

Studied in

Aequorea victoria

Sample size

protein isolated from many thousands of jellyfish

Aequorin emits light in response to calcium rather than requiring the usual luciferin–luciferase arrangement, and the preparation also contained a separate green fluorescent protein.

• A biochemical characterisation, which says nothing about what the jellyfish uses its light for.
• Required enormous numbers of animals by modern standards, which is part of why the work would be done differently today.

• Bioluminescence

  The work that isolated a jellyfish’s light protein also noted a second protein that glowed green. That one — GFP — became the standard way of making things visible inside living cells, which nobody was trying to invent.