Abstract: Provided is a derivative of 22-hydroxycholesterol, 24S-hydroxycholesterol, 25-hydroxycholesterol, 26-hydroxycholesterol or 27-hydroxycholesterol. Also provided is a protein conjugated to the above derivative. Further provided is an antibody composition comprising antibodies that specifically bind to 22-hydroxycholesterol, 24S-hydroxycholesterol, 25-hydroxycholesterol, 26-hydroxycholesterol or 27-hydroxycholesterol. Additionally, a method of making antibodies that specifically bind to 22-hydroxycholesterol, 24S-hydroxycholesterol, 25-hydroxycholesterol, 26-hydroxycholesterol or 27-hydroxycholesterol is provided. Also, a method of assaying for 22-hydroxycholesterol, 24S-hydroxycholesterol, 25-hydroxycholesterol, 26-hydroxycholesterol or 27-hydroxycholesterol is provided. Additionally provided is a kit for detecting 22-hydroxycholesterol, 24S-hydroxycholesterol, 25-hydroxycholesterol, 26-hydroxycholesterol or 27-hydroxycholesterol.