Old in-situ hybridization protocols require murine tissues to be fixed with PFA pH9.5, but I was wondering if the newer RNAscope technnology allowed us to work with tissues fixed at physiological pH.
I routinely do RNAscope, HCR, and classic whole mount in situ on mouse embryos, they both work very well with 24h+ fixation in 4%PFA obtained by diluting 32% PFA in 1X RNA grade PBS (made with DEPC water) without adjusting the pH.