During mixing in standard DURAN® GLS 80® laboratory bottles, the liquid moves in a swirling motion that approximates a solid-body rotation. This is a very inefficient flow pattern, and very little mixing actually occurs. By adding three vertical baffles into the inner surface of the DURAN® GLS 80® bottles, the swirling motion is disrupted and an improvement of the top-to-bottom circulation occurs which produces a greater radial and more effective mixing.