Radioisotopes as Tracers of Synthetic Polymers in the Body

Radioactive labelhng is based on either incorporation of the radioisotope into the polymer structure or on attachment of a radioactive tag to the polymer. All labelling methods are well known and have frequently been described however, they may also be a source of certain pitfalls. These questions will be discussed later. 

The attachment of a radioactive tag to the polymer is a much more versatile method however, inherent changes of the macromolecule may result. The significance of these alterations should be assessed from the viewpoint of the purpose of the experiment. A compromise between this and the former method involves the use of a radioactive polymerization initiator which is incorporated into the polymer chain. However, the specific activity which can be achieved is very low. 

It follows from the labelling procedures discussed above that and C nuclides are most often incorporated into the polymer molecule, as heteroatoms (S, P, etc.) 

it should be noted that each decay is accompanied by a chemical transmutation H - He, -4 - S, - C1. The daughter atom receives the 

In conclusion, radioactive labelling is a method of choice of a very sensitive tracing of the polymer and its possible metabolites in bulk biological material. It is less suitable for morphological analysis. Care must be taken to check for alternation of the polymer properties, the stability of the label and for radiochemical and radiobiological side-effects. 

---