Probing for PTH1R revealed strong bands at 115 kDa and several less predominant bands amongst them at 68 kDa. The predicted molecular weight of the receptor is 66 kDa, however, the reference blots from the antibody supplier further present bands at 117 kDa, 56 kD and 82 kDa, similar to our observations. It was observed that extending denaturation at 95 °C would increase the band at 66 kDa. It is hypothesized that the strong bands at 115 kDa originate from PTH1R, which in absence of ligands has been reported to form dimers . While there is no consensus about PTH1R expression in the HEK293 cell line, the anti-PTH1R AB staining revealed its presence in all cell lysates, concurring with previous reports . Densitometric analysis of the PTH1R blot showed a modest increase in PTH1R expression in the stable transfectants.