Figure 100.

Identification of B cells expressing different Immunoglobulin heavy chain isotypes in a human PBMC sample (healthy individual age 47, male). (A) Lymphocytes were identified based on their FSC and SSC, Doublet exclusion was performed on FSC-H vs FSC-A, and B cells were gated as CD19⁺ and zombie yellow (viability dye) negative. (B) Non-switched B cells (IgD⁺) and class-switched (IgM-IgD−) were gated. (C) Within the IgM-IgD− population, IgA⁺ B cells, IgA2⁺ and IgA⁻ cells can be distinguished. IgA1⁺ B cells were defined as IgA⁺IgA2⁻. (D and E) IgA− B cells were further differentiated based on expression of IgG1, IgG2 (D), IgG3 and IgG4 (E).