Fig. 8. Intracellular CA125-C-TERM is localized to organelles of the classical ER/Golgi-dependent secretory pathway. HeLa_MCAT-TAM2 cells stably expressing CA125-C-TERM were grown on glass cover slips. At about 70% confluency, cells were treated with brefeldin A (5 µg/ml) for 60 minutes or were left untreated as a control. Following fixation with paraform aldehyde, cells were treated with Triton X-100 to allow intracellular staining of antigens using antibodies directed against calreticulin, the KDEL receptor and CA125. Double staining was performed using secondary antibodies coupled to Alexa-488 and Alexa-546, respectively. Specimens were analyzed with a Zeiss LSM510 confocal microscope. (A) Anti-calreticulin, not treated with brefeldin A; (B) anti-CA125, not treated with brefeldin A; (C) anti-KDEL receptor, not treated with brefeldin A; (D) anti-CA125, not treated with brefeldin A; (E) anti-KDEL receptor, treated with brefeldin A; (F) anti-CA125, treated with brefeldin A.