Approximate computing stands out in systems in which the simplicity must be above the demand for high precision and processing speed. It is the case of DNA systems, especially those based on the DNA strand displacement technique, which is naturally in a complex and noise-filled environment. In this sense, proposals for approximate DNA circuits implemented with an analog approach promise future disease diagnosis applications, for example. In this paper, we adapted a multiplication gate presented in the literature in order to reduce the influence of leak reactions. For this, we insert drain species after some time at the beginning of the process. Next, we built a DNA analog circuit using the multiplication gate with the extended addition and subtraction gates, proposed earlier, to solve a simple expression. The results showed that our modification significantly reduced the effects of leaks and the implemented circuit has an adequate accuracy with an acceptable error when their inputs species present median concentrations.

近似计算在系统的简单性必须高于对高精度和处理速度的要求的系统中脱颖而出。DNA系统就是这种情况，尤其是基于DNA链置换技术的系统，它自然是在复杂且充满噪音的环境中。从这个意义上讲，以模拟方法实现的近似DNA电路的提议有望在未来的疾病诊断应用中得到应用。在本文中，我们采用了文献中介绍的乘法门，以减少泄漏反应的影响。为此，我们在流程开始一段时间后插入排水物质。接下来，我们使用前面提出的具有扩展加法和减法门的乘法门构建了一个DNA模拟电路，以解决一个简单的表达式。