An improved calibration procedure for computer-based quantitative autoradiography utilizing a mathematical model for the non-linear response of camera and film.

A mathematical model which accounts for the non-linear response of both the camera and film in computer-aided quantitative autoradiography is derived. This model and the algorithm to fit the data for radioactive standards by a non-linear least-squares procedure to this model are described. The usefulness of this technique is demonstrated by employing it to analyze a set of 14C-labeled brain paste standards which were exposed to Ultrofilm in such a way that the full response range of the film was used. This technique can be readily implemented on most commercially available image analysis systems and is compatible with most types of video cameras.