Hey Zhi, 

In my experience (with primary rat cortical and DRG, and mouse hippocampal neurones culture) the B27 supplement was not harmful at all, rather it improved the viability.  I have even used the same B27 along with retinoic acid for differentiating h-shsy5y cells and it did not alter the outcome. May be you should check composition of your B27, some commercial providers include retinoic acid and others don't, I suppose it would make some differences if you plan to achieve differentiation as an end result. Hope it helps.

Best luck for your experiments !

Nand 

Thank you so much Nand.

I compare the differentiation of neurosphere with Neurobasal(only) and Neurobasal+B27+LG. Cells differentiated from Neurobasal medium were more than the medium plus B27+LG. I am thinking about whether it is because B27 could inhibit the astrocyte differentiation. 

Do you have some experience? Thank you so much.

Dear Zhi,

I've used the B27 for my neurospheres as well as for Astrocytes and Neurons differentiation. I used 3% B27 (50X) from Gibco along with   0.5% N2 (100X), 1% ABAM, 1% glutamax, 1% BSA and EGF for the first stages of proliferation then I switch the media by just replacing the EGF with FCS (still with B27) for the differentiation stages.The media improved my cells viability and proliferation. Basically, the astrocytes differentiation was very normal and their viability was perfect in the media containing the B27.

Hope you're gap is solved soon.