Hello Everyone,

I'm conducting a study of cholesterol assimilation of bacteria in MRS (de Man, Rogosa, Sharpe) broth media , I need to perform o-phthalaldehyde method for cholesterol quantification. To do this, I have to prepare a cholesterol stock solution in advance, i decided to choose absolute ethanol for dissolving cholesterol. However, I have not known exactly optimal conditions for preserving the stock solution.

Does cholesterol in a stock solution degrade over time? If so, what is the degradation time?