With the rapid development of the internet technology, the blended learning mode plays a more and more important role in education reforms by integrating traditional classroom teaching and online learning. WeChat is the most popular Chinese social software, and its public platform is also suitable for mobile learning. Here, we report an application of the blended learning method based on WeChat public platforms in microbiology breeding experiment courses, using the site-directed mutagenesis of the green fluorescent protein (GFP) as an example. The learning process was divided into five modules: teaching design, learning resource preparation, pre-class learning, classroom learning, post-class review and evaluation. By introducing one mutation (Y66H) in mutagenic primers, the mutated GFP gene was amplified by PCR using pGFPuv as templates, followed by removal of the original plasmid template by DpnⅠ digestion. Students can monitor the color changes from green to blue in the fluorescence emission of the mutated proteins. As a useful addition to classroom teaching, WeChat is suitable for students to use fragmented time to learn and improve teaching interaction. Learning assessment results revealed the blended learning environment improves students’ study interests and self-learning abilities, thus achieving a fruitful teaching result.