I am currently engaged in cfDNA extraction, and capillary electrophoresis analysis reveals peaks for DNA ranging from 400 to 1000 bp. I employ silica spin column in my extraction process, Ana I'm confident that the sample contains cfDNA since a parallel extraction using a commerical kit shows a peak at 130-180 bp in capillary electrophoresis analysis. Can anyone provide insights into the potential reasons behind the absence of peaks for smaller fragments in my current extraction method ?

Thank you in advance