Szm745

We tested the whole genome of 20 HeLa-CCL2 cells. As control, 10 normal human leukocytes from the blood of a healthy volunteer were also sequenced. Add 3 volumes of red blood cell lysis buffer (RBC Lysis Buffer, CWBiotech) to the blood sample and put the sample on ice for 15 minutes. Then centrifuged the sample at 1200 rpm for 5 minutes to removed supernatant and add 1.0 ml DPBS (1X Dulbecco’s Phosphate Buffered Saline, without calcium and magnesium, Corning) to resuspend the leukocytes. Single cells were captured by mouth pipette under the stereomicroscope (Nikon SZM745). The single-cell DNA amplification was followed by the MALBAC technique developed by Xie’s laboratory [14 (link)]. After amplification, six genomic loci were checked in the samples by qPCR before generating library to make sure the DNA was well presented as quality control (QC). We picked the sample with over two detectable loci to generate library. The sequencing depth for a single cell was 0.3X (about 1G per cell).

We randomly chose 720 HeLa-CCL2 cells (288 from the 9^th passage, 288 from the 14^th passage and 144 from the 20^th passage) in this work on an Illumina HiSeq 4000 platform (sequenced by Novogene, China) for 150 bp paired-end sequencing. The protocol was totally followed Tang’s modification on SMART-Seq2 [21 (link)]. Single cells were captured by mouth pipette under the stereomicroscope (Nikon SZM745) and followed by the protocol [21 (link)]. Every cell was assigned with 250 M raw data on average.