Hi, I have been using GCRMA and checking today the histograms it seems that the distribution (for expressions vals of probes on a single chip) is not symmetric at all, rather toward left. Is it normal? MAS5 is very symmetric in distrib of probe intensities (after log2). Also since the distrib for GCRMA is not symmetric it is wise to scale the data between chips? If you have any suggestions please let me know. Radu -- Dr. Radu Dobrin Department of Molecular Biology Princeton University Washington Road Princeton, NJ 08544-1014 Phone: 609-258-5657 E-mail: rdobrin@molbio.princeton.edu

> > I have been using GCRMA and checking today the histograms it seems that > the distribution (for expressions vals of probes on a single chip) is > not symmetric at all, rather toward left. Is it normal? MAS5 is very The distribution of expressions does not have to be symmetric at all. If you expect similar levels of up-regulation and down-regulation, the distribution of "difference in expression" should be symmetric. > symmetric in distrib of probe intensities (after log2). Also since the > distrib for GCRMA is not symmetric it is wise to scale the data between > chips? > > If you have any suggestions please let me know. > > Radu > > -- > Dr. Radu Dobrin > Department of Molecular Biology > Princeton University > Washington Road > Princeton, NJ 08544-1014 > Phone: 609-258-5657 > E-mail: rdobrin@molbio.princeton.edu > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor >