Going through my RNA-seq samples, I've noticed this weird pattern for 'per base sequence content' graph.

[http://imgur.com/bhYIVJT][1]

There is a lot of noise in the first few base pairs and I was curious what it is and if I should be concerned for not reducing the noise before alignment.


  [1]: http://imgur.com/bhYIVJT
Here is a [link][1] (for a post by Dr. Simon Andrews, author of FastQC) to put this topic to rest. Short answer: Nothing to worry about or mitigate.


  [1]: https://sequencing.qcfail.com/articles/positional-sequence-bias-in-random-primed-libraries/