Metadata

Filename	21C125_R1.fastq.gz
Filesize	0.45 GiB
Filename read 2	21C125_R2.fastq.gz
Filesize read 2	0.46 GiB
Sequali version	1.0.1

Read 1: Summary

Mean length	151.00
Length range (min-max)	151	151
Total reads	5,477,353
Q20 reads	5,147,175	93.97%
Total bases	827,080,303
Total GC bases	273,860,586	33.11%
Q20 bases	798,680,482	96.57%

Read 2: Summary

Mean length	151.00
Length range (min-max)	151	151
Total reads	5,477,353
Q20 reads	5,182,064	94.61%
Total bases	827,080,303
Total GC bases	273,545,195	33.07%
Q20 bases	797,522,582	96.43%

Read 1: Sequence length distribution

Read 2: Sequence length distribution

Read 1: Per position quality score distribution

Read 2: Per position quality score distribution

Read 1: Per position quality percentiles (approximation)

Shows the mean for all bases and the means of the lowest and highest percentiles to indicate the spread. Since the graph is based on the binned phreds, rather than exact phreds, it is an approximation.

Read 2: Per position quality percentiles (approximation)

Shows the mean for all bases and the means of the lowest and highest percentiles to indicate the spread. Since the graph is based on the binned phreds, rather than exact phreds, it is an approximation.

Read 1: Per sequence average quality scores

>=Q5	5,477,353	100.00%
>=Q7	5,477,352	100.00%
>=Q10	5,477,328	100.00%
>=Q12	5,477,287	100.00%
>=Q15	5,470,227	99.87%
>=Q20	5,147,175	93.97%
>=Q30	1,962,703	35.83%

Read 2: Per sequence average quality scores

>=Q5	5,477,353	100.00%
>=Q7	5,477,349	100.00%
>=Q10	5,477,286	100.00%
>=Q12	5,476,997	99.99%
>=Q15	5,461,081	99.70%
>=Q20	5,182,064	94.61%
>=Q30	1,537,904	28.08%

Read 1: Per position base content

Read 2: Per position base content

Read 1: Per position N content

Read 2: Per position N content

Read 1: Per sequence GC content

For short reads with fixed size (i.e. Illumina) the plot will look very spiky due to the GC content calculation: GC bases / all bases. For read lengths of 151, both 75 and 76 GC bases lead to a percentage of 50% (rounded) and 72 and 73 GC bases leads to 48% (rounded). Only 74 GC bases leads to 49%. As a result the even categories will be twice as high, which creates a spike. The smoothened plot is provided to give a clearer picture in this case.