title: GSM6502245: K7_3_2; Homo sapiens; miRNA-Seq
library_construction_protocol: Total RNA was extracted from 10–30 mg of each placental sample using the Allprep DNA/RNA/miRNA Universal Kit (50), catalogue no. 80224 (Qiagen, Nordic, Sollentuna, Sweden) according to the manufacturer´s instructions. RNA yield and purity were determined with a Nano-Drop ND-1000 Spectrophotometer (Nano-Drop Technology, Wilmington, DE, USA), and RNA quality was evaluated using an Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA, USA) according to the manufacturer´s instructions, as previously reported (10). All nineteen samples of RNA were of high quality with an optical density 260/280 ratio of 1.8–2.2 and an RNA integrity number ≥ 8. Small RNA libraries were generated with Illumina's Small RNA sample preparation protocol (TruSeq Small RNA Sample Prep Kits (Illumina, San Diego, CA, USA)) according to the manufacturer's instructions