The BIAS (Biological Image Analysis System) was developed to: (i) permit accurate entry and image processing of biological data; (ii) minimize the need for specialized hardware; and (iii) aid in the human genome mapping and other projects. The first mouse/cursor key-driven module was designed to be user interactive and readily accessible to many laboratories. It contains the DRSNDS programs which automate the entering of data in a systematic format. The types of data that can be entered utilizing this module are DNA-RNA gels from either a positive or negative Polaroid image, autoradiograms or biotinylated images from Southern, Northern and dot or slot blot hybridization analyses. The image is acquired using a video camera and then digitized for subsequent analysis. During the analysis graphical representations of the intermediate results are provided to assure user confidence. At any point within the program the user may obtain on-line help with the current task. The output displays the mol. wt of each individual component in the appropriate context. The present version of the program produces results comparable with a human interpreter for some data. Band shifting and optical density calculations are in a prototype form to permit evaluation of various techniques. Future work is directed at expanding the system's capabilities to interpret data from other biological analyses including DNA sequencing gels.