Hello Dear Friends,
I am looking at my current miRNAseq data which was prepared with Illumina TruSeq small RNA sequencing kit.
One weird thing came to me is, the top abundant sequence reads that are actually around 1/4 of the total reads is:
And the second abundant read is actually just one nucleotide shorter:
After trimming the adapter TGGAATTCTCGGGTGCCAAGG, the sequencing reads indicate that more than 50% of total reads are pointing to one microRNA (miR-486). This definitely is really weird.
Have anyone seen this before? Is this possible in blood samples? Or this might be due to the library prep method? Or I am using the wrong way to look at these reads?
Can anyone give me some comments or hints? Thank you very much!