33P - A SUPERIOR RADIOTRACER FOR PHOSPHORUS

Phosphorus-33 has half-life and energy properties which should render it superior to 32P as a radiotracer for phosphorus in most biological applications. It should be particularly useful in autoradiography, in long-term experiments, in applications where sensitivity to radiation is high and in dual labelling of intermediates containing more than one phosphorus atom. Advantages and limitations in the use of 33P are reviewed with a consideration of price, half-life, energy, radioisotopic purity and methods of measurement. Determination of the 32P content in 33P is used to demonstrate Geiger, liquid scintillation and Cerenkov techniques for counting these radioisotopes. © 1969.