Cell Sorting Strategies:
In the case of the marrows, live cell sorts were divided into two fractions based on forward scatter and side scatter characteristics—a lymphoid and progenitor fraction and a granulocyte fraction. This allowed for the relative enrichment of lymphoid and progenitor cells in the overall analysis, advantageous for our goal to investigate B cell developmental trajectories. By nature of this sorting strategy, our marrow data does not reflect whole kidney marrow composition. Between 50,000 and 100,000 cells were sorted per sample.