Page 283 - Radiochemistry and nuclear chemistry

Uses of Radioactive Tracers 267

9.5.1. Biological affinity

To study how living species interact with the environment, ecology, one can use
radioactive tracers to follow the uptake of a trace metal (e.g. cobalt) from the soil by
plants, and by animals after having eaten the plant. In agriculture, this is useful in studying
the uptake of trace elements necessary for plant growth. For example, it has been found
that sheep need plants containing selenium in order to combat white muscle disease. The

kidney
brain 3 skelet, musc. 40 lung 82 spleen 44 pancreas 21 cortex 153

eye myocard 50 heart blood 100 liver 84 intestine 377 testis

FIG. 9.12. Autoradiograms, (a) distribution of 14C-PAS in a mouse 30 minutes after intra-
venous injection, (b) of HeLa-cells labeled by 3H-thymidine. (From Hanngren and Nias.)