Abstract: The present invention provides a method and a kit for assaying a TSH receptor antibody, which are easy to manipulate and are safe. Specifically, the present invention provides a composition comprising a genetically modified cell forced to co-express a TSH receptor, a cyclic nucleotide responsive calcium channel, and a luminescent protein aequorin. Use of the composition enables the assay of a TSH receptor antibody contained in a sample.

Abstract: Provided are a procedurally simple and safe method and kit for measuring the concentration in a biological sample of a physiologically active substance which binds to a receptor that causes a change in intracellular cAMP concentration. By providing a composition including genetically-modified cells which show co-expression of a receptor that causes a change in intracellular cAMP concentration, a cyclic nucleotide-responsive calcium channel, and aequorin luminescent protein, it is possible to measure how much of a physiologically active substance which binds to said receptor is included in a biological sample.

Abstract: The present invention provides a method and a kit for assaying a TSH receptor antibody, which are easy to manipulate and are safe. Specifically, the present invention provides a composition comprising a genetically modified cell forced to co-express a TSH receptor, a cyclic nucleotide responsive calcium channel, and a luminescent protein aequorin. Use of the composition enables the assay of a TSH receptor antibody contained in a sample.

Abstract: Provided are a procedurally simple and safe method and kit for measuring the concentration in a biological sample of a physiologically active substance which binds to a receptor that causes a change in intracellular cAMP concentration. By providing a composition including genetically-modified cells which show co-expression of a receptor that causes a change in intracellular cAMP concentration, a cyclic nucleotide-responsive calcium channel, and aequorin luminescent protein, it is possible to measure how much of a physiologically active substance which binds to said receptor is included in a biological sample.

Abstract: The present invention provides a method and a kit for assaying a TSH receptor antibody, which are easy to manipulate and are safe. Specifically, the present invention provides a composition comprising a genetically modified cell forced to co-express a TSH receptor, a cyclic nucleotide responsive calcium channel, and a luminescent protein aequorin. Use of the composition enables the assay of a TSH receptor antibody contained in a sample.

Abstract: To measure a receptor-mediated increase in intracellular calcium concentration, use is made of a calcium-responding luminescent protein localized in the cytoplasm or mitochondria and a reporter gene having a promoter responding to the second messenger in cells and Renilla-origin luciferase attached to the downstream thereof. By using a coelenterazine derivative, which can exist in the cells in a stable state over a long time, as the substrate of these proteins, a transient increase in the intracellular calcium concentration observed within several seconds is measured by using the calcium-responding luminescent protein. Subsequently, the cells are allowed to survive and cultured for several hours as such without adding a fresh substrate. During this period, an increase/decrease in the gene expression is continuously monitored by the reporter assay method and it is measured and evaluated, if necessary, whether or not the inhibition of the activity is caused by cytotoxicity.