Gradient slopes,

ρ_e/ρ_c versusL/R_p, from FIMD analysis (Figure 4C) of both normal and Rh_null cells. Slopes of FIMD analysis are indicative of cytoskeletal attachment. Results for CD47 and RhAG suggest a cytoskeletal attachment similar to one another and intermediate to glycophorin C and the lipid bilayer. CD47 retains this attachment in the absence of the Rh proteins in Rh_nullcells. The connectivity, f*, of CD47 and RhAG can be determined from these FIMD slopes (Table 1).