title: The Use of Legendre and Zernike Moment Functions for the Comparison of 2-D PAGE Maps.
abstract: The comparison of 2-D maps is not trivial, the main difficulties being the high complexity of the sample and the large experimental variability characterizing 2-D gel electrophoresis. The comparison of maps from control and treated samples is usually performed by specific software, providing the so-called spot volume dataset where each spot of a specific map is matched to its analogous in other maps, and they are described by their optical density, which is supposed to be related to the underlying protein amount. Here, a different approach is presented, based on the direct comparison of 2-D map images: each map is decomposed in terms of moment functions, successively applying the multivariate tools usually adopted in image analysis problems. The moments calculated are then treated with multivariate classification techniques. Here, two types of moment functions are presented (Legendre and Zernike moments), while linear discriminant analysis and partial least squares discriminant analysis are exploited as classification tools to provide the classification of the samples. The procedure is applied to a sample dataset to prove its effectiveness.
authors.affiliation: Department of Sciences and Technological Innovation, University of Piedmont Orientale, Viale Michel 11, 15121, Alessandria, Italy. emilio.marengo@uniupo.it.
authors.forename: Emilio
authors.initials: E
authors.lastname: Marengo
authors.affiliation: Department of Sciences and Technological Innovation, University of Piedmont Orientale, Viale Michel 11, 15121, Alessandria, Italy. elisa.robotti@uniupo.it.
authors.forename: Elisa
authors.initials: E
authors.lastname: Robotti
authors.affiliation: Department of Sciences and Technological Innovation, University of Piedmont Orientale, Viale Michel 11, 15121, Alessandria, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Demartini
mesh_terms: D016002:Discriminant Analysis; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods / Q000706:statistics & numerical data*; D016018:Least-Squares Analysis; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification*; D040901:Proteomics; D012984:Software
chemical_list: D011506:Proteins
keywords: Classification; Image analysis; LDA; Legendre moments; Moment function s; PLS -DA; Zernike moment s