Automated analysis of electrophoretic gels by image digitalization and processing

In this paper a system and method of automated analysis of electrophoresis gels by image digitalization and processing are reported. The image digitalization system is formed by a non-intensified colour charge-coupled device camera interfaced to a microcomputer through a frame grabber that allows image acquisition to be performed in real time. The illumination and image acquisition conditions will be discussed. A few different macro routines for image processing and data analysis were built. They were designed to cope specifically with the different requirements of the analysis of the different types of electrophoresis gel employed. After selection of the appropriate routine the automated evaluation process begins with digitalization and processing of the images in order to enhance the contrast of the images and to detect relevant features. The image-processing techniques employed include histogram equalization and contrast enhancement, noise reduction by low-pass Fourier filtering, edge enhancement and location by the application of differential operators, posterization or binarization, and blob analysis, matching and feature extraction. The obtained images are also compressed and stored on the patient's files for future reference.