Direct analysis for cholesterol in gallstones by use of differential scanning calorimetry transition phase

A cholesterol transition phase at 37.5 degrees C has been shown by use of a Differential Scanning Calorimeter. The transition, reversible and reproducible, is useful for analytical purpose. We propose an analytical method for cholesterol in gallstones based on this transition. The method requires no intermediate reactions and cholesterol can be assayed directly in the powdered stone, with no other pretreatment or reagents. The analysis is highly specific, requires about 10 min, and is quite precise (CV about 1.5%) and accurate (about 2%).