Usually between 150 and 300µm you should be ok

This atlas is pretty precise for these kind of questions

http://mouse.brain-map.org/experiment/thumbnails/100048576?image_type=atlas

cheers

Thanks a lot but do u start reset the stereotactic from the skull surface or when u about to touch the cortex itself? Have u tried viral vecto delivery L2-3?

If yes, how much did u inject? Which serotype?

You should reset it from the cortical surface of dura when it is still intact. For layer 2/3 specific expression either you need to inject a very low amount very slowly like 100-200nl over 3-5min at around 150µm. Or you go angular around 60-70° and inject a similar volume around 150-250µm depending how much of an angle you use. I personally only have experience with AAV2.

That’s great advice. I also use AAV . May i kno about the serotype u used , the injected volume, and spreadability area?

An excellent reference for all your aav serotype and spreadability questions is this one Article Analysis of Transduction Efficiency, Tropism and Axonal Tran...

I used aav2 and got between 400µm to a milimeter approximately depending on the angle and the volume injected.