Oil red O preparation - (Jan/26/2013 )

Hi,

Very simple stuff but I am annoyed with it,
I am trying to stain lipid droplets in cells using Oil Red O.
I had a previous batch of the stock solution that was perfect, no aggregates, very clean, and nice staining but I have tried to prepare some new from powder (0,5g in 100mL isopropanol), heating overnight at 56C and filtering twice in whatman paper but even with this and after additional filtration, I get a lot of aggreagates on my cells when observing in microscope.

I prepare my working solution from stock (I tried 6:4 and 3:1 ORO/water ratio) used immediately with and without filtering before adding to the slides, I wash with water several times but it doesnt seem to help

The solution I make, 0,5g ORO in 100mL isopropanol, seems very dark compared to the previous one but I think this is the usual concentration though....

If anyone has a way of doing it that works, I'd be pleased to know about

Thanks

Actually I never did this but often it helps when such stuff is really a powder without any larger parts and if you dissolve it bit by bit and not the whole amount at once. or just buy a ready-made solution.