Radioactivity and the biology teacher

Abstract

A considerable proportion of biology teachers in schools and technical colleges are at present using or contemplating using radioactive isotopes for certain experiments in their courses. These experiments (a general list appears at the end of the article) are easy to perform and usually biologically instructive. For the teacher the experiment naturally does not stop with performing it; solutions have to be prepared, supervision and suggestions have to be given to students concerning data handling, half-life and self-absorption corrections, etc. An awareness of the pitfalls in both technique and result interpretation has to be gained and this is usually not possible even in an intensive one week course that most teachers have attended. For this reason this article covers the minimum necessary nuclear fundamentals such as levels of activity, specific activity and the use of carrier materials. The way the isotope is assayed and the corrections that need to be made or taken into account to obtain a valid resu...