Use of Glucose labelled with Carbon-14 to determine the Amino-Acids Essential for an Insect

Abstract

A CHEMICALLY defined diet is required for determining essential dietary components by the classical deletion procedure. It has proved difficult to rear plant-feeding insects on artificial diets^1,2. A method that would permit the determination of essential factors such as amino-acids for insects not reared on chemically defined diets would be useful. In 1952, Steele³ showed that carbon-14 appeared in the non-essential but not in the essential amino-acids when uniformly labelled sucrose-¹⁴C was ingested by a mouse. This finding provides the basis for an indirect method of determining which amino-acids are essential in the diet. The present report compares results of the indirect method with those of the classical deletion procedure⁴ for the blowfly Phormia regina Meig.