Fig. 4. Immunocytochemistry of CHO cells expressing WT-ACE or GPI-ACE. (A) and (B) CHO cells transfected with WT-ACE and GPI-ACE, respectively were subjected to immunocytochemistry using the polyclonal anti-ACE antibody RP183 as described in Materials and Methods. (C and D) CHO cells transfected with WT-ACE and GPI-ACE, respectively, were incubated for 20 minutes at 4°C with 2% (v/v) Triton X-100 prior to paraformaldehyde fixation and subsequent immunocytochemistry using the polyclonal anti-ACE antibody RP183, as described in Materials and Methods.