I collected ISF from the mouse hippocampus using a CMA probe for 25 hours, varying the collection speed. I aimed to measure Tau levels and used an ELISA kit, but no Tau proteins were detected. I initially used aCSF as perfusion buffer and later switched to aCSF with 100mM KCl to stimulate the neurons, but still did not detect any Tau.

I had no issue regarding the collection volume (they all were equal)