A general method for the one-dimensional quantitative analysis of band profiles from an autoradiographed or stained gel is described. Curved lanes may be tracked, noise across the width of the band reduced by local averaging of densities within a selected window, and background-corrected density profiles produced. Sections of each profile can be subjected to a choice of three methods of peak-area determination, depending on the type of gel and the requirements of the analysis being carried out. In the first method, simple integration is used to measure the area under the profile between any two positions. The second method integrates a Gaussian distribution fitted to a single peak. Where bands overlap, the third method resolves peaks into their component areas, taking into account the observed increase in the width of the band in the direction of electrophoretic migration. This is incorporated into a least-squares profile-fitting method, which is shown to be both accurate and efficient.