Entering edit mode
7.2 years ago
tunl
▴
90
I got a length distribution of a PacBio RNA-seq sample. There is a really tall peak (at least a magnitude higher than the majority) at a very narrow range of short lengths. I was wondering what might be the possible reasons for such a narrow tall peak at short lengths?
Any advice would be greatly appreciated.
Thank you very much in advance!
Do they all have a similar sequence? What's the organisms?
The sequence lengths range from < 100 to about 14k. It's a human sample. Thanks a lot!
I don't have enough experience with human samples. It might be a specific ncRNA, it also depends on the library preparation protocol, especially RNA selection (poly-A selection, ribo-zero etc.). I suggest to look at their sequences or map them independently.
Which aligner did you use? Difficult to tell without commands and a screenshot.
They have not been aligned yet. Thanks!
It's unclear how the library was prepared, but could those reads be rRNA?
It used polyA RNA. Thanks a lot!