Microdetermination of Calcium by Aequorin Luminescence

Abstract
A bioluminescent protein, aequorin, isolated from the jellyfish Aequorea in dilute disodium ethylenediaminetetraacetate solution, emits light on addition specifically of Ca++ or Sr++, thus providing the basis for a simple, quantitative micromethod for the determination of these cations, especially in biological fluids.