In order to remove batch-to-batch technical variation we follow [ 23] and apply ComBat [ 24].
TOYOTA and its Lexus division are having problems with vehicles that leak oil and transmission fluid, leaks that were noted in the latest batch of technical service bulletins.
BRUSSELS, Nov. 23 — Microsoft submitted a new batch of technical information about its Windows operating system to the European Commission on Thursday, meeting the latest deadline to provide information on whether it is complying with a 2004 antitrust ruling.
Because sample networks often reveal groupings of samples that reflect batch effects (technical variation), which are typically not removed by standard normalization procedures, we have also incorporated existing methods that allow the user to automatically correct for batch effects.
DNA methylation arrays are susceptible to batch effects: technical remnants that are not associated with the biological question but with unrelated factors such as laboratory conditions or experiment time (Leek et al, 2010; Sun et al, 2011b).
We visually inspected the scatterplots of the first vs. the second components from a principal component analysis of the 4 CpGs, according to different variables to observe potential batch effects (technical and not attributable to covariables).
Samples are unavoidably run in multiple batches due to technical and time constraints, making batch effects a source of non-biological variation that can increase error [25], [26].
Thus, our conclusions (of high overlap across species), are conservative with respect to the technical batch effect.
All tissues used for downstream studies were prospectively randomized during processing and sectioning, prior to expression analysis, to minimize technical batch effects in the data.
It is remarkable that we have been able to observe this considerable conserved chromatin signature despite the obvious confounding technical batch effect in these comparative data.
