Icons - Feedback appreciated

I'm working on a set of icons for an infographic showing the process of a medical technique. Overall I am happy with how these have turned out so far, but the third icon (the darkest blue) isn't quite doing it for me. This step illustrates cells multiplying. I would love for there to be more white, but still maintain consistency with the other icons. These will be large, so view the 2x for all the detail. Any feedback is welcomed!