Hi Heba,

we have always kept our cell lysis buffer at 4 degree. However, we add fresh protease inhibitors before use.

You can make a concentrated stock of PI (25X or 100X) and add the protease inhibitor to the amount of RIPA you need to lyse your cells. 

Dear Heba,

I have used RIPA before, but I am a bit confused about what you mean by "safely". Any how, I think it is okay for you to aliquote in eppendorfs. I think it should be fine since inside a box in a freezer/fridge they won't get much light. You can also wrap them in aluminium foil if that still worries you.

Thanks I will alliquote but have 500 ml bottle needed many hours to melt at room temp. Wondering if it is ok to put few minutes in incubator . 

Hi Heba,

we have always kept our cell lysis buffer at 4 degree. However, we add fresh protease inhibitors before use.

You can make a concentrated stock of PI (25X or 100X) and add the protease inhibitor to the amount of RIPA you need to lyse your cells.