Tracking Tau in Neurons: How to Grow, Fix, and Stain Primary Neurons for the Investigation of Tau in All Developmental Stages.

Primary neurons have proved to be an invaluable tool for the investigation of Tau in the context of neuronal development and neurodegeneration. Culturing neurons usually is time consuming and requires multiple feeding steps and media exchanges, and either the use of proprietary media supplements or tedious preparation of complex media. Here we describe a relatively cheap and easy cell culture procedure based on a commercially available neuronal culture supplement (NS21) of known composition, as well as basic fixation techniques. Further, we demonstrate a staining technique that can be carried out in pre-coated hydrophobic multi-well plates, which minimizes antibody consumption and allows fast and convenient processing of samples for immunofluorescence microscopy of endogenous Tau in primary neurons. We also provide a protocol that allows cryopreservation of fixed cells for years without loss of Tau stainability.