A Laboratory Class: Constructing DNA Molecular Circuits for Cancer Diagnosis

It has been shown that active learning strategies are effective in teaching complex STEM concepts. In this study, we developed and implemented a laboratory experiment for teaching the concepts of Boolean logic gates, molecular beacon probes, molecular computing, DNA logic gates, microRNA, and molecular diagnosis of hepatocellular carcinoma, which are related to DNA molecular computing, an interdisciplinary cutting-edge research technology in biochemistry, synthetic biology, computer science, and medicine. The laboratory experience takes about 110–140 min and consists of a multiple-choice pretest (15 min), introductory lecture (20 min), wet laboratory experiment (60–90 min), and a post-test (15 min). Students are tasked to experimentally construct three molecular logic circuits made of DNA oligonucleotides and use them for the fluorescence-based detection of microRNA markers related to diagnostics of hepatocellular carcinoma. The class was taught to undergraduate students from freshman to senior academic levels majoring in chemistry, biochemistry, biotechnology, and biomedical sciences. Students were engaged during the session and motivated to learn more about the research technology. A comparison of students’ scores on the pretest and post-test demonstrated improvement in knowledge of the concepts taught. Visual observation of the fluorescence readout led to a straightforward interpretation of the results. The laboratory experiment is portable; it uses inexpensive nontoxic reagents and thus can be employed outside a laboratory room for outreach and science popularization purposes.