2.3. Single-Cell Library Preparation and mRNA Sequencing (scRNA-Seq) of Proliferative Phase Endometrial Cells with 10× Genomics

The endometrial cell suspensions were delivered to the Eukaryotic Single Cell Genomics Facility (ESCG, SciLifeLab, Stockholm, Sweden), prepared and loaded on a 10× Genomics Chromium Controller instrument for single-cell gel bead-in-emulsion (GEM) formation and barcoding using the Chromium Single Cell 3′ Gel Bead Kit v2. GEM reverse transcription was performed. Once cDNA was generated, amplified by polymerase chain reaction (PCR) and cleaned, the sequencing libraries were constructed according to the manufacturer’s instructions using the Chromium Single Cell 3′ Library Kit v2 (10× Genomics).

Three runs of scRNA-seq of uncultured endometrial cells were performed with one run per sample (n = 3). Each run consisted of one sample/sequencing lane using the Illumina 2500 instrument. Approximately 3000 cells were sequenced per sample with an average sequencing depth of 50,000 reads per sample.