Spot Edge Detection in Microarray Images Using Bi-Dimensional Empirical Mode Decomposition

A Deoxyribonucleic Acid (DNA) microarray is a collection of microscopic DNA spots attached to a solid surface, such as glass, plastic or silicon chip forming an array. The analysis of DNA microarray images allows the identification of gene expressions to draw biological conclusions for applications ranging from genetic profiling to diagnosis of cancer. The DNA microarray image analysis includes three tasks: gridding, segmentation and intensity extraction. During the processing of microarray images, the irregularities of spot position and shape could generate significant errors. This paper presents an edge detection method using Bi-dimensional Empirical Mode Decomposition. Application of edge detection technology on separating spots form the background decreases the probability of errors and gives more accurate information about the states of spots. The proposed method identifies the spots with low density, thus increasing the performance of microarray images.