Dear Vaishali,
I am afraid you might have miss-interpreted some part of our article. It is not possible to isolate active and quiescent NSCs from the brain directly for IHC and FACS. What we did was to isolate neural stem cells (bulk) and culture them in vitro.
In a more recent paper, we performed single cell RNAseq from tissue and could identify active and quiescent cells, if that will be interesting for you, please check this reference:
https://doi.org/10.1016/j.stem.2021.01.003
Best of luck with your experiments,
Noelia