I'm using Dorsomorphin (C24H25N5O) as one component in dual SMAD inhibition of pluripotent stem cells to differentiate into neurons alongwith SB431542.

Now as to solubilizing 10mg SB in DMSO for 50mM stock I had no issues as it readily dissolved and gave very clear solution. I dissolved 5mg Dorsomorphin in 1.2mL of DMSO keeping in mind DMSO toxicity limit for cell culture. When seen in light for brief the Dorsomorphin solution wasn't 100% clear and crystals were reflecting light. But I still carried on making my solutions and then filtering this. My dual SMAD inhibition has failed. When I used 0.5mg dorsomorphin in 1ml DMSO , I had no issues in my experiment and it worked.

Sigma also states that solubility in DMSO > 2mg/mL.

I need confirmation of indeed my solution is saturated and it may be cause of failure. I also want to know if Dorsomorphin di hydrochloride can be used for dual SMAD inhibition in place of Dorsomorphin?