ChIPexoQual

ChIPexoQual provides a quality control pipeline of ChIP-exo nexus/data. It allows the quick evaluation of ChIP-exo/nexus data quality by directly operating on aligned read files and without requiring any complex statistical modelling or intensive computation such as identification of potential binding regions/events. This enables its broad application and versatile utility, and provide easy data evaluation before any statistical analysis for identifying binding events.

The overall pipeline follows the steps:

1. Partitions the reference genome into islands representing overlapping clusters of reads separated by gaps.
2. Calculates a set of summary statistics.
3. Visualize the data with a collection of diagnostic plots aimed at quantifying ChIP enrichment and strand imbalance.
4. Generates quantitative summaries of these diagnostic plots.

This version includes two additional modules:

a) ExoDataSubsampling to subsample N1 < … < N reads and repeat the the first 4 steps.

b) ExoDataBlacklists to partition the ChIP islands into two collections based on their overlap with a set of blacklisted regions.

To install the package, it is easiest to use:

#install.packages("devtools")
source("http://www.bioconductor.org/biocLite.R")
biocLite("BiocInstaller")
devtools::install_github("welch16/ChIPexoQualExample")
devtools::install_github("welch16/ChIPexoQual",ref = "devel")

References

Welch R, Chung D, Grass J, Landick R, and Keles S. “Data Exploration, Quality Control, and Statistical Analysis of ChIP-exo/nexus Experiments” (in preparation)