Preheat the oven to 325 degrees. Butter the bottom and sides of a 9x5 loaf pan.
In a medium sized mixing bowl, whisk or sift together the flour, baking soda, baking powder, and salt. Set aside when finished.
In a large mixing bowl, cream together the butter and sugar until EXTREMELY light and fluffy, 3-6 minutes.
Add the eggs, one at a time, mixing just until the yellow disapears. Add the lemon juice, lemon zest, and sour cream and mix just until combined.
Stir in the flour mixture in batches just until well incorporated in the wet ingredients.
Toss the blueberries in 1/2 tablespoon of flour. This will help them to not sink to the bottom of the cake.
Gently fold 1 cup of blueberries into the batter, reserving the final 1/2 cup of berries to sprinkle on top of the cake after it is in the pan.
Pour batter into a buttered bread loaf pan and sprinkle remaining berries on the top.
Bake for 50 to 65 minutes until a toothpick inserted into the center of the cake comes out clean.
Cool in the pan for 15 minutes before removing to a wire rack to finish cooling down.