Fig. 4: Sanger sequencing validation of multiple V(D)J recombination patterns in single B cells.

a Sketching diagram of the single-cell sequencing procedure. We isolated peripheral blood from healthy donors and separated peripheral blood mononuclear cells (PBMCs). Naive B cells (CD19⁺CD38^+/−CD10^-CD27⁻), memory B cells (CD19⁺CD38^+/−CD10^-CD27⁺), and plasma cells (CD19⁺CD38⁺⁺⁺CD10⁻) were sorted by FACS. The total mRNA in single B cells was reverse transcribed, and the Ig heavy chain and light chain were amplified by multiplex PCR. FACS, fluorescence-activated cell sorting. b Proportions of cells expressing VDJ recombination patterns in single B cells from donor 7, donor 8, and donor 9. c–e Distribution and frequency of IGHV (c), IGHD (d), and IGHJ (e) segments in Ig germline genes in a single cell. f Proportions of single naive B cells, plasma cells, and memory B cells expressing one, two, or three V_HDJ_H segments. g, h Proportions of single B cells expressing one, two, or more V_κJ_κ segments (g) and V_λJ_λ segments (h). i Counts of single B cells expressing only Igκ or Igλ or expressing both Igκ and Igλ. j, k Proportions of naive B cells, plasma cells, and memory B cells expressing one, two, three, or four Ig classes