Help needed - What is the influence of high degree of cholesterol in liposome composition (1/3 (Jun/28/2006 )

I've tried to prepare SUV as a part of DRV preparation (using sucrose), but I don't get a translucent solution (hazy) after 40 minutes (netto) of bath sonication. Might it be because the high degree of cholesterol in liposome composition? Am I supposed to get the translucent solution with cholesterol? What are the conditions for getting translucent solution with bath sonicator or tip(prop) conicator.

Thanks in advance

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Can you tell me the lipid composition (the type of phospholipid that you used as bulk lipid) and have you removed the organic solvant with high vaccum (oil pump) for a good 2hr? Did you form a thin lipid layer on the glass tube or flask? Did you allow at least 30 min incubation time at the right temp with periodical vortex after you added buffer solution? Did you use a temperature that is slightly above the Tm of the phosphalipid that you are using?

I have not used this type of sonicator before. I hope it is not the one used for cleaning purpose, coz that will be too weak. I recommend you to use either a probe sonicator or a special bath sonicator. Probe sonicator is very powerful, you need to put your sample on ice during sonication to prevent over heat which causes lipid oxidation. Go to Avanti Polar Lipids website to find out more details. Typically, people incorporate up to 30% chol. When use sonicator, you do it in sessions utill it becomes clear to translucent, kind of like adding one drop of milk to a glass of water.

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