A low-priced computer-assisted densitometer and analysis software for quantitative autoradiography.

A computer-assisted densitometer which consists of a darkroom enlarger, a black-and-white exposure meter, an amplifier, an analog-to-digital converter, and a microcomputer with a monitor and a graphic printer can be utilized for the quantitative analysis of autoradiograms. QUANTAR, a computer program written in BASIC, records the density measurements and stores the data in a file that can be easily retrieved by commercially available spreadsheet software. A spreadsheet template was designed to convert the digital readings into concentration of ligand in tissue. A variety of spreadsheet templates can be created to analyze data for a standard curve, a Scatchard plot, or a binding competition curve. This system, which is easy to assemble, may be useful to the frugal investigator with a modest equipment budget.