Detection of Thyroid-Stimulating Antibody Using Frozen Stocks of Chinese Hamster Ovary Cells Transfected with Cloned Human Thyrotropin Receptor.

To measure thyroid-stimulating antibody (TSAb) in sera from patients with Graves' disease, we developed a new assay system with using frozen stocks of CHO-K1 cells. CHO-K1 cells transfected with cloned thyrotropin (TSH) receptor on a 96 well plate were frozen in Cell Banker and stored at -70 degrees C. Three days before the assay, they were thawed in the culture medium and allowed to grow in a monolayer until use. The medium was replaced with medium containing IgGs from the patients, then after 2 h, it was collected and concentrations of adenosine 3'-5'-cyclicmonophosphate (cAMP) were measured. This method is sensitive enough to detect TSAb and it is simpler and easier than the methods which use FRTL-5 cells.