Yes, but if using cultured buttermilk, I add 1/4 tsp of baking soda to offset the acid in the butter milk. If I'm using buttermilk left from making butter, I substitute equally for sweet (regular) milk.
Not sure what the general opinion of this is but I use powdered buttermilk as it keeps a lot longer in the fridge. Not forever, but I never seem to be able to use one quart, which is the smallest size I can get it in.
I use buttermilk in my my muffins all the time, yes the recipe calls for baking soda and the uncooked miz lasts for weeks although the color of the mixture changes slightly