title: GSM8070230: SKN_cell; Homo sapiens; miRNA-Seq
library_construction_protocol: Total RNA was extracted from EVs and cultured cells using QIAzol Lysis Reagent and the miRNeasy Mini Kit (QIAGEN, Hilden, Germany). RNA concentration was measured using a NanoDrop ND-1000 spectrophotometer (Thermo Fisher Scientific). Small RNA libraries were prepared using the NEBNext Multiplex Small RNA Library Prep Set for Illumina (New England Biolabs, Ipswich, MA, USA) according to the manufacturer's instructions. The small RNA libraries (cDNAs) were purified using a QIAquick PCR Purification Kit (Qiagen) and separated by gel electrophoresis (6% TBE gel, 120 V, 60 min). DNA fragments corresponding to 140–160 bp (the length of small noncoding RNA plus the 3′ and 5′ adaptors) were recovered and the cDNA concentration was measured using the Qubit dsDNA HS Assay Kit with a Qubit 4 Fluorometer (Thermo Fisher Scientific).