To all the brilliant scientists out there,

Recently I've been performing single cell DNA library for NGS illumina, and there was an issue that bothers me for weeks, I wonder has anyone encountered the same situation or understand what is the problem.

When I checked my library size on a Bioanalyzer, I noticed there were adapter dimers, so I tried a reduced AMPure XP bead ratio (from the recommended 0.8X twice to 0.7X twice) for library clean-up, and I found I can almost remove all the empty adapters.

However when I analyzed sequencing data from these 2 library: 0.8X twice VS 0.7X twice, I found the mapping rate was 40% VS 10%, I wondered if this is because I reduced the bead ratio, which cause the loss of a good proportion of my fragment?

My expected length is ≥ 300 bp.

Thank you so much for all your help!