Dr. Levin collaborated with Dr. Jochen Buck to purify and clone mammalian soluble adenylyl cyclase (sAC, ADCY10). Working together, Drs. Buck and Levin demonstrated that sAC activity is directly regulated by bicarbonate ions and functions as a biological sensor for carbon dioxide, bicarbonate, and pH. Our joint laboratory developed the most widely used genetic, pharmacologic, and immunologic reagents for studying sAC, and we demonstrated genetically and pharmacologically that sAC in sperm is essential for male fertility. Most recently, our work focused on developing small molecule drug-like sAC inhibitors into on-demand contraception for men and women.