Immunoblot of Lu and GPC in Triton shells prepared from resealed red cell ghosts. The Triton shells were prepared from ghosts resealed without or with increasing concentrations of αR4 or αR5 as described in “Triton extraction of erythrocyte ghosts.” Proteins retained in the Triton shells were analyzed by SDS-PAGE and immunoblotted with anti-Lu and anti-GPC. Note the progressive decrease of Lu in αR4-resealed ghosts (A) but not αR5-resealed ghosts (B). GPC was unchanged in αR4-resealed ghosts (C).