English: The panel shows DNA fragment size distributions as obtained by Bioanalyzer DNA-1000 assays. The curves represent the size fractions removed during the first separation step A) or recovered after the second separation B). The two size fractions were independently reproduced in 4 or 8 separation experiments. The curves in B) represent the libraries sequenced after dSPRI based size selection, adapter ligation and PCR enrichment. While concentrations (arbitrary fluorescence units) vary between reproduced libraries the range of removed or enriched DNA fragment sizes was highly reproducible. Panel c) shows the DNA fragment size distribution recovered after the second separation when using decreasing amounts sheared genomic DNA. dSPRI allows reliable size selection in a DNA concentration independent manner.