Sequencing libraries of capped and non-capped small RNAs from the THP-1 cell line.

5’ cap structure plays a very important role in the biological system, as it for instance regulates RNA stability and localization. These libraries are part of an intensive study of the cap structure of short RNAs (sRNAs), using three different methods: thin layer chromatography, mass spectrometry, and sequencing. For sequencing, we prepared a multiplexed library (SRig10043) with a standard adaptor ligation procedure, using THP-1 small RNAs immunoprecipitated with anti-cap antibodies and pre-treated with phosphatase and pyrophosphatase to make them competent for ligation. We also prepared two multiplexed libraries (S91 and S92), from THP-1 small RNAs, where we replaced the 5'' adapter ligation step by template-switching in order to add the adapter to capped and non-capped RNAs. These libraries were then fractionated in three size ranges, 1-50, 50-150 and 1-200, to separate known sRNAs from potential smaller processing products.