How long is the storage life for all trans retinoic acid stock in -80 C - (May/14/2010 )

Dear all,

May I know how long do you store your all trans retinoic acid stock in -80 C? Sigma provides 50 mg per vial (Cat# R2625), which when reconstitute in ethanol, yield 16.6 ml in volume (0.01M stock), which is a LOT! The recommended storage is merely 2 weeks at -80 C.

The RA is used for cell differentiation experiment. In my hand, using it for few months still induces differentiation of cells to neuronal cell type. But the concern is that, will there be variation in results due to "expired" stocks.

Thanks in advance

Hi Isek,

I have only started to work on retinoic acid and have been using the retinoic acid kept in the -80 for more than a year! Seemed to be working in my hand, at a relatively low dose (200 nM).


The retinoic acid was disoolved in Ethanol and aliquots into small aliquots and we will discard the remaining retinoic acid after we took it out from -80.

Thanks WYF