A microdensitometer for quantitative determination of relative densities of photographic negatives of tissue cells

• Publisher: Elsevier Science
• Year: 1946
• Tongue: English
• Weight: 160 KB
• Volume: 242
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(46)90574-1

✦ Synopsis

A densitometer has been constructed for examination of photomicrographic negatives of individual cells. When monochromatic light is passed through thin sections of tissue some areas absorb more light than do others. For this reason when photomicrographs are taken of such tissue the film density varies in different areas inversely with the amount of light absorbed by the corresponding areas of the tissue section. Cell nuclei of biological material absorb light in varying degree depending on the wave length used. Visual observation of the film or of photographs made from such fihn is not sufficiently precise for accurately recording the differences of absorption at various wave lengths. This instrument was designed to make such measurements accurately and in such a way that the results could be recorded in numerical values.