A new approach for normalization of DNA-microarray data
نویسندگان
چکیده
Signal data from DNA-microarray “chip” technology contains various artifacts from the fabrication process and it is inherently noisy. In order to detect the systematic errors and to reduce the noise contained in the experimental data, replications of the experiments are made. Therefore the crucial point in obtaining biological information out of the experimental data is the use of advanced normalization techniques which enable to detect and to correct for systematic errors. In this paper we present an iterative nonparametric non-linear normalization algorithm based on the Alternating Conditional Expectation (ACE) algorithm. Our modified algorithm constructs so called optimal transformations which minimizes the pairwise deviations of all replications within one biological sample. This new normalization method is compared with linear procedures such as mean or median normalization. In a comparative study with 132 Affymetrix chips in 22 experiments, it is shown that this new algorithm yields a significant reduction of systematic noise when compared with other linear normalization techniques. This method can be easily extended to normalization of chips belonging to two different samples and it is equally applicable to other DNA-microarray technologies, e.g. two-color chips.
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تاریخ انتشار 2001