Sample 472_p
Peritoneal lavage was collected following the instructions described previously43. Briefly, ice-cold DPBS was injected into the abdominal cavity. After massaging the peritoneum, the peritoneal fluid was collected by a needle with a syringe. The lavage was centrifuged at 400 x g for 7 min. Lysing Buffer (Thermo Scientific). Peritoneal B cells were enriched with the CD19 MicroBeads (Miltenyi Biotech).  C57BL/6 wild-type mice were used for scRNA-seq and scBCR-seq. The Bcl11aeGFP mice were previously described42. The Rag2-/- mice (008449) were purchased from the Jackson Laboratory. All mice used were maintained under a specific pathogen-free condition at the Laboratory Animal Research Center of Tongji University. All experiments were approved by the Biological Research Ethics Committee of Tongji University. scRNA-seq libraries were prepared following the SMART-seq2 protocol44. Single cells were directly sorted into 96-well plates containing the lysis buffer and external RNA spike-ins (Ambion) (1:500,000). The reverse transcription and pre-amplification were performed, then the amplified cDNA products were purified.  Quality control was performed by checking the size distribution of cDNAs. Multiplex (96-plex) libraries were constructed and amplified using the Nextera XT library preparation kit (Illumina). The libraries were then purified and the quality of the library is assessed by the Bioanalyzer (Agilent) before submission to the DNA sequencing pipeline.