Before accepting a position at FIU in August, 1994, Darrow served as Chief of the Behavioral and Prevention Research Branch, Division of STD/HIV Prevention, at the National Center for Prevention Services of the Centers for Disease Control and Prevention (CDC). Darrow has published over 100 scientific papers in professional journals, books, and research monographs.
His role in the discovery of the AIDS virus, HIV, was described by Randy Shilts' 1987 book And the Band Played On. Darrow also appeared in "The Zero Factor," part one of the four-part documentary, A Time of AIDS, which was shown on the Discovery Channel.
At the CDC, Darrow's work primarily focused on the social variables of sexually transmitted diseases, especially among homosexual men. In 1981, his focus shifted from condom use and diseases such as syphilis and gonorrhea to HIV/AIDS. Since then, Darrow has devoted his study and career to finding a cure for HIV/AIDS.