A schematic summary of the adhesion assay.

LTBMCs are established from female BALB/c mice and maintained for 4 weeks. (A) The supernatant cells are removed and the stromal layers washed. (B) Fresh male BALB/c marrow is harvested into LTBMC medium and inoculated onto the pre-established stromal layers. (C) The cultures are incubated for the adhesion step, during which time any experimental manipulations to explore the in vitro homing process can be carried out. (D) After the adhesion time, the supernatant media and cells are removed and counted; samples can be taken for fluorescence in situ hybridization (FISH) for other analyses. (E) The stromal layers are washed; then the adherent cells are harvested by mechanical dissociation and studied. (F) Cells are counted, and the percentage of male cells in the adherent layer is determined by FISH. (G) Cells are transplanted into lethally irradiated female BALB/c recipients, in competition with freshly harvested female marrow. (H) The percentage of male chimerism in female recipients is used to determine the engraftment capability of adherent male cells.