An easily constructed and inexpensive three-layer cassette for tritium-sensitive film autoradiography

This report describes the design, construction, and use of a three-layer photographic cassette that is suitable for tritium-sensitive film autoradiography. The cassette can be produced easily and at a fraction of the cost of commercially available cassettes. The three-tiered design allows for the simultaneous exposure of 108 standard-sized glass microscope slides to three 20 X 34 cm pieces of 3H-Ultrofilm (LKB). The small between- or within-film variation of gray values recorded for either background, tritium-containing standards, or neighboring brain sections labeled with 3H-spiroperidol demonstrates the reliability of the cassette for autoradiographic quantification of tritium label.