Radioautographic visualization of newly synthesized proteins: a critical appraisal

The radioautographic detection of newly synthesized proteins depends on: the choice of the tracer which is guided by several factors (L-amino acid with a high specific activity, a non-exchangeable radioactive atom, a reduced number of catabolic products, an easy extraction with a fixative); the choice of the fixative (high extractive power of the free and adsorbed amino acids, efficient insolubilization of cellular proteins). In any case the combination of biochemical, pharmacological and physiological resorts is a peremptory requirement to decide whether after the administration of a labelled amino acid the radioactivity visualized by the silver grains of radioautographs results or not from the manufacture of new proteins