Our basic technology: positron emitting radiotracers
Tracer can be detected non-invasively due to the high energy of the decay products which can penetrate through many cm of plant tissue or from roots through soil. Tracer can be administered repeatedly, because the isotopes are short-lived and repeated doses do not accumulate. Experiments can use multiple tracers to study a variety of physiological traits in an individual plant, or repeated measures for longitudinal studies, for example to follow a developmental time course, or to follow the response to stress. Perhaps most important, positron-emitting tracers can be administered at concentrations 3-4 orders of magnitude lower than other radioisotopes (e.g., carbon-14), at true tracer levels without disturbing the biochemical or hormonal homeostasis in the plant.
The positron emitting radioisotopes are produced in a cyclotron and then converted to desired chemical forms for use in plants. Because of their short half-life, the isotopes must be produced where they are used, and this is the main reason—apart from cost—that they have been used so little in plant science, and in only a handful of locations worldwide. BNL is home to two cyclotrons, the Ebco TR-19 and JSW cyclotrons.
Integrated Plant Radiotracer Laboratory
The BNL facility is unique in that it combines standardization of technology offering parallel tracer studies and system automation enabling turn-key operation that is appealing
to plant biologists.
for studies of amino acid metabolism and transport. Just as CO2 is the substrate for plant carbon assimilation (via Rubisco), nitrate is reduced to ammonia, and ammonia is the substrate for amino acid synthesis. Labeled ammonia gas at high specific activity, can be supplied to leaves at a very low concentration with little to no physiological effect, offering a way to infuse a radioactive probe into the plant’s nitrogen metabolic pathways.
Radiotracer residing within the plant’s tissues/organs is detected via its decay products—either the positrons directly or subsequent annihilation photons.
Summary of Core Capabilities
Last Modified: February 7, 2013