Artefacts in radioautography

Factors, other than radiations emitted by the tracer, which can affect the nuclear emulsion coating the tissue section, are reviewed. The background fog corresponds to spontaneously developable grains in an emulsion unexposed to radiations. Besides the radioautographic reaction produced by the radioactive atoms experimentally introduced in the tissue, various ionizing radiations may give rise to silver grains. When the underlaying tissue displays an irregular relief, mechanical artefacts may be produced. Chemoautography is an artefact resulting from a chemical interaction between the underlaying tissue and the nuclear emulsion