Immunoblot analysis of digoxigenin-labeled calreticulin. Fetuin (control glycoprotein) and purified calreticulin (CRT) from either HL-60 or Sf9 cells were incubated in Endo F buffer with (+) or without (−) N-glycosidase F (N-Glyc F ), then oxidized with periodate and derivatized with digoxigenin. The proteins were then analyzed by 7.5% SDS-PAGE, transfer to nitrocellulose and immunoblotting with either antidigoxigenin (upper panel) or anticalreticulin (lower panel). The blots are arranged as indicated with paired lanes (minus or plus N-glycosidase F ) for each of the three proteins.