title: GSM5945521: gastric cancer cells SNU_exosome_rep2; Homo sapiens; Human gammaherpesvirus 4; miRNA-Seq
library_construction_protocol: Total RNA was extracted from cells and exosomes using the high pure RNA extraction kit (TRIzol) in accordance with the manufaxturer's protocol. The OD260 and OD280 values and ratios of 1μL extracted samples were determined by ultraviolet spectrophotometer to determine the concentration and purity of extracted samples. Approximately 1 μg of total RNA from each sample was used to prepare the miRNA sequencing library. The strips between 17 and 32 nt were cut by polyacrylamide gel electmphoresis（PAGE) and the products were recycled. T4 RNA ligase (Epicenter, San Diego, CA, USA) was used to connect the isolated small RNA to the 3' end and then the isolated small RNA to the 5 'end using the same method. The sRNA connected by the connector was used as the template for RT-PCR, and the single-stranded cDNA template was amplified into double-stranded cDNA, and then PCR amplification was conducted. Then the gel was cut and the target fragment library was recycled. The constructed library was used to detect quality and yield using Agilent 2100 Bioanalyzer and ABI StepOnePlus Real Time PCR System. The library with qualified quality test was sequenced.