1. Preheat oven to 400 degrees F.
2. In a large bowl, whisk together flours, wheat germ, baking powder, baking soda, and salt.
3. Cut the butter into the flour mixture until the mixture resembles coarse crumbs. Add the buttermilk and stir just until a moist dough forms.
4. Turn the dough out onto a generously floured work surface and roll the dough into a 1/2" thick rectangle. Using a biscuit cutter dipped in flour, cut out biscuits. Gather the scraps and roll out to make additional biscuits.
5. Place the biscuits about 1" apart on an ungreased baking sheet. Bake until the biscuits rise to twice their unbaked height and are lightly golden (8-10 minutes).