Open chromatin assays show distinct fragment length enrichments, as the cut
sites are only in open chromatin and not in nucleosomes. As such, peaks
representing different n-nucleosomal (ex mono-nucleosomal, di-nucleosomal)
fragment lengths will arise. Good libraries will show these peaks in a
fragment length distribution and will show specific peak ratios.
NFR: Nucleosome free region
Sequence quality metrics (filtered/deduped BAM)
rep1
Open chromatin assays are known to have significant GC bias. Please take this
into consideration as necessary.
Annotated genomic region enrichment
rep1
Fraction of Reads in universal DHS regions
0.5550666627774995
Fraction of Reads in blacklist regions
0.008064604501082765
Fraction of Reads in promoter regions
0.2675188142430547
Fraction of Reads in enhancer regions
0.3497486272819322
Signal to noise can be assessed by considering whether reads are falling into
known open regions (such as DHS regions) or not. A high fraction of reads
should fall into the universal (across cell type) DHS set. A small fraction
should fall into the blacklist regions. A high set (though not all) should
fall into the promoter regions. A high set (though not all) should fall into
the enhancer regions. The promoter regions should not take up all reads, as
it is known that there is a bias for promoters in open chromatin assays.
Replication quality metrics
Number of raw peaks
rep1
Number of peaks
274169
Top 300000 raw peaks from macs2 with p-val threshold 0.01
Peak calling statistics
Peak region size
rep1
Min size
150.0
25 percentile
235.0
50 percentile (median)
396.0
75 percentile
650.0
Max size
2661.0
Mean
489.7627448763354
rep1
Enrichment / Signal-to-noise ratio
Jensen-Shannon distance (filtered/deduped BAM)
rep1
AUC
0.13171461709128215
Synthetic AUC
0.49526922566236026
X-intercept
0.14627143788262298
Synthetic X-intercept
0.0
Elbow Point
0.8507375551316962
Synthetic Elbow Point
0.49894246485937405
Synthetic JS Distance
0.5569124077140174
Peak enrichment
Fraction of reads in peaks (FRiP)
FRiP for macs2 raw peaks
rep1
Fraction of Reads in Peaks
0.4894493018742062
For macs2 raw peaks:
repX: Peak from true replicate X
repX-prY: Peak from Yth pseudoreplicates from replicate X
pooled: Peak from pooled true replicates (pool of rep1, rep2, ...)
pooled-pr1: Peak from 1st pooled pseudo replicate (pool of rep1-pr1, rep2-pr1, ...)
pooled-pr2: Peak from 2nd pooled pseudo replicate (pool of rep1-pr2, rep2-pr2, ...)
For overlap/IDR peaks:
repX_vs_repY: Comparing two peaks from true replicates X and Y
repX-pr1_vs_repX-pr2: Comparing two peaks from both pseudoreplicates from replicate X
pooled-pr1_vs_pooled-pr2: Comparing two peaks from 1st and 2nd pooled pseudo replicates