Western Blots of Whole-Cell Lysates of Transiently Transfected COS1 (A and B) and JEG3 (C and D) Cells and Stably Transfected Flp-in 293 Cells (E). The cells were transfected with WT or mutant hMCT8 without and with CFP tag. The MCT8 constructs with and without CFP tag show a specific monomer band and a homodimer band. The blots show a specific MCT8 monomer band of 60 000 (ie, without CFP) and approximately 87 000 (ie, with CFP) and a homodimer band of 120 000 (ie, without CFP) and 174 000 (ie, with CFP). hGAPDH was used as a housekeeping protein. A and B, Lanes in 10% SDS-gels (A) and in 8% gels (B) were loaded with 25 μg protein of whole-cell lysates of transiently transfected COS1 cells. C and D, Lanes in 10% (C) and 8% (D) SDS-gel were loaded with 25 μg protein of transfected JEG3 cells with WT or mutant MCT8 with or without CFP tag. E, 50 μg protein of stably transfected Flp-in 293 was loaded onto 10% SDS-gel per lane. Immunoblots were carried out at least two times per cell line.