Fig. 2.

Detection of non-human sRNA species in column eluates and their removal from columns: a qPCR amplification of six non-human sRNA species in extracts from human plasma and qPCR control (water). b Detection of the same sRNA species in mock extracts without input to extract columns and water passed through extraction columns (‘eluate’). c Levels of the same sRNA species in mock extracts without and with DNase treatment during the extraction. d Relative levels of sRNA remaining after pre-treatment of extraction columns with bleach or washing ten times with water, detected after eluting columns with water. All: mean results of three experiments, measured in reaction duplicates; error bars represent one standard deviation; data points are available in Additional file 2: Tables S7–S10. Experiments displayed in panels b and d were performed on the same batch of columns, a and c on independent batches