System for accurate one-dimensional gel analysis including high-resolution quantitative footprinting.

The interactive menu-driven computer program, Geltrak, displays and analyzes a one-dimensional (1-D) electrophoretic gel after digitization by either densitometry or storage-phosphor technology. The program is designed to analyze nucleic acid or protein gels in a variety of ways and includes a specific footprinting option. Overall accuracy for the entire process of 1-D electrophoretic gel band quantitation by peak profile fitting has been investigated. A standard control gel with a predetermined component ratio and minimal background was devised and subjected to electrophoresis, followed by three methods of digitization. The resulting images were analyzed by Geltrak, and their integrated peak area ratios were compared with their initial measured values. Individual band profiles from the control gel were used to develop an improved fitting function to represent the peak profile shape exactly. This function can be used in conjunction with a sophisticated profile-fitting technique to accurately predict the peak shapes from gels with background noise or overlapping bands.