Method for detecting intracellular cholesterol

1. A method of inhibiting over accumulation of cholesterol intracellularly in cells comprising administering to the cells a cholesterol inhibitor identified by a method comprising exposing mutant NPC1 cells to a test agent, permeabilizing the mutant NPC1 cells, evaluating the intracellular level of cholesterol accumulation in the permeabilized mutant NPC1 cells exposed to the test agent via binding of labeled C theta complex to cholesterol-rich domains in intracellular organelles, and comparing the evaluated level to the intracellular level of cholesterol bound to labeled C theta complex in mutant NPC1 cells not exposed to the test agent, wherein a decrease in the level of cholesterol accumulation intracellularly in the mutant NPC1 cells exposed to the test agent as compared to the intracellular level in mutant NPC1 cells not exposed to the test agent is indicative of the test agent being a cholesterol inhibitor.

2. A method of inhibiting over accumulation of cholesterol intracellularly in cells comprising administering to the cells a cholesterol inhibitor identified by a method comprising exposing mutant NPC1 cells to a test agent, permeabilizing the mutant NPC1 cells, evaluating the intracellular level of cholesterol accumulation in the permeabilized mutant NPC1 cells exposed to the test agent via binding of labeled C theta complex to cholesterol-rich domains in intracellular organelles, and comparing the evaluated level to the intracellular level of cholesterol bound to labeled C theta complex in parental cells not exposed to the test agent, wherein the intracellular level of cholesterol accumulation in the mutant NPC1 cells exposed to the test agent is equal to the intracellular level of cholesterol in the parental cells not exposed to the test agent is indicative of the test agent being a cholesterol inhibitor.