In vitro colonization of thymic primordia by adult bone marrow cells: light scatter profile and separation by flow cytometry.

Adult mouse bone marrow showed a reproducible scatter profile on low angle vs. right angle scatter by flow cytometry and it was possible to sort cells from different regions of the profile. The colonization of the third pharyngeal pouch in vitro was used as a test of thymocyte precursors. Alleles of the Thy-1 surface antigen, as well as the nuclear chromatin pattern of the ichthyosis mutant, were used to monitor chimerism. Thymus-colonizing cells were found in one region of the scatter profile, and these cells were negative for Thy-1 and Ia markers.