I have tried to dissolve it by heating the cholesterol in water as 0.3mg/100mL under stirring, but still it not dissolving. Is there any parameters like pH or some other thing to adjust, so as to dissolve it in water?
We usually use choloroform at a concentration of 100mg/ml for the initial dissolution and then its further dilutions can be made in your specific solvent (we make in cell culture media)
This lipid will not dissolve in water by adjustig pH or temperature unless you make any specific drug delivery using organic solvents.
Here is the solubility of Cholesterol MSDS:
Cholesterol monohydrate is practically insoluble in water (less then 0.5 mg/100 ml of water); slightly soluble in alcohol (1.29% w/w at 20 °C), more soluble in hot alcohol (100 g of saturated 96% alcoholic solution contains 28 g at 80 °C). Also one gram dissolves in 2.8 ml of ether, in 4.5 ml of chloroform, and in 1.5 ml of pyridine.
The product is soluble in acetone, dioxane, ethyl acetate, benzene, petroleum
ether, oils, fats, and in aqueous solutions of bile salts.
You did not mention the need for you to dissolve cholesterol and use. You can dissolve choesterol in a small volume of alcohol and add required amount of distilled water or buffer. I think this will give you a suitable solution (emulsion?). You may want to see a research article @ http://www.clinchem.org/content/20/4/482.full.pdf though not sure if it can help you.
you can dissolve it in 1% Triton in CHCl3 then Dry under N2 until CHCl3 is completely evaporated after that Add MQ-H2O and Incubate for 5 min at 60 C and by doing that you can make all the lipid including cholesterol water soluble considering the concentration of lipids in your samples you adjust the triton and water...
Cholesterol, as noted above by our colleagues, is virtually insoluble in water and lacks any groups that charges can be altered by adjusting the pH. I think Anika's point about cyclodextran is one approach as the cholesterol will be in the cyclodextran molecule and come out essentially when it bumps into a suitable acceptor such as a cell membrane.
However, as noted by Amaravadi, one important question is why is this important? When posing a question such as this, it is important first to convey the reasons behind the question. Do you want to incubate cells with cholesterol? If so, adding it in EtOH is one solution, but even then the cholesterol will not truly be in solution as the EtOH disperses. The cyclodextran is another route as well. Additionally, various detergents can be used, similar to the classic mechanisms of dispersing TAG droplets in a sink full of dishes, detergents will keep the cholesterol dispersed in solution. So, a water soluble detergent would be another viable approach.
All in all though, framing the question would be most helpful to achieve the best results from the world's scientific community.
I am probing the interaction of various molecules in a liquid interface. The material that i am using is an O/W emulsion. I want to know the effect of cholesterol in an oil/water interface. Since the continuous phase is water, i need to have a sample which is water soluble. That's why i want cholesterol which is soluble in water.
I suggest using cyclodextrin which is easily solubilized in water. Another suggestion is to use a small amount of organic solvent, such as hexane or isopropanol (0,3 mg cholesterol with 0.1-0.5 mL organic solvent) and add water to terminate the solution (99.9-99.5 mL water). I do not know if these solvents interfere with your system, need to evaluate this issue.