Investigation of the Cholesterol Biosynthesis by Heart-Cut Liquid Chromatography and Mass Spectrometric Detection

•Development of a heart-cut LC-MS method for analyzing the cholesterol biosynthesis.•Method allows the detection of cholesterol and low-abundance sterol intermediates.•Effective across various biological matrices such as cells or plasma.•Inhibition experiments confirm that biological responses can be measured. The biosynthesis and homeostasis of cholesterol are essential for cellular function. Cholesterol is a major lipid with multiple roles in membrane stability, signaling, or as a precursor for other molecules. Because of the structural similarity of the sterols involved in the biosynthesis, their accurate identification and quantification is still challenging. Moreover, the huge difference in the concentration of cholesterol and its precursors can cause interferences during the detection. To overcome these problems, a heart-cut liquid chromatographic method was developed by evaluating 38 different columns to achieve optimal separation. The method efficiently separates all sterol biosynthesis intermediates, with detection limits in the low nmol/L-range and an upper limit of quantification of 9 mmol/L for cholesterol by using triple quadrupole mass spectrometric detection. Investigation of lung carcinoma cells treated with statins demonstrated the capability to detect a biological response, showing inhibition of sterol synthesis. This technique offers a robust tool for studying cholesterol biosynthesis and its role in disease.