Thinking beyond fluorescence: biological imaging with SHG and THG microscopy

In modern life science research, fluorescence microscopy is a popular and powerful imaging technique. Yet, despite its overall success, the need for fluorescent labels limit its potential applications. How can we image beyond fluorescence microscopy? With fluorophores specifically labeled on a target, the emitted fluorescence signal can provide superb imaging contrast with minimal background down to the molecular level. Highly developed optical technologies, as well as extensive labeling approaches from cutting-edge genetic engineering, are the success factors of fluorescence microscopy in biological research. Yet, despite its overall success, the need for fluorescent labels or molecules still limits the applications of...