In today's world DNA technology is promoted as an alternative approach for advancement over silicon technology. The DNA technology is also used to detect diseases. It needs some molecular computation for which the development of basic circuit unit is required. Basic circuit comprises the AND, OR and NOT gate. In this paper we proposed the design of two-input OR gate with E6 deoxyribozyme whose internal loop is not fixed. OR logic helps to express Boolean expression in Sum of Product (SOP) form and sometimes it uses to minimize the Boolean function. The DNA technology can be used as a substitute method not only for lower time complexity and low power consumption but also this technology is reversible in nature. © 2013 Springer.