Sierra Platinum is a fast and robust peak-caller for replicated ChIP-seq experiments with visual quality-control and -steering. The required computing resources are optimized but still may exceed the resources available to researchers at biological research institutes. Sierra Platinum Service provides the full functionality of Sierra Platinum: using a web interface, a new instance of the service can be generated. Then experimental data is uploaded and the computation of the peaks is started. Upon completion, the results can be inspected interactively and then downloaded for further analysis, at which point the service terminates.
DNA bound proteins such as transcription factors and modified histone proteins play an important role in gene regulation. Therefore, their genomic locations are of great interest. Usually, the location is measured using ChIP-seq and analyzed using a peak-caller. While replicated ChIP-seq experiments become more and more available, they are still mostly analyzed using methods based on peak-callers for single replicates. The only exception is PePr, which allows peak calling of several replicates. However, PePr does not provide quality measures to assess the result of the peak-calling process. Moreover, its underlying model might not be suitable for the conditions under which the experiments are performed. We propose a new peak-caller called `Sierra Platinum' that not only allows to call peaks for several replicates but also provides a variety of quality measures. Together with integrated visualizations, the quality measures support the assessment of the replicates and the resulting peaks. We show that Sierra Platinum outperforms methods based on single-replicate peak-callers as well as PePr using a newly generated benchmark data set and using real data from the NIH Roadmap Epigenomics Project.
