Recently, the internationally renowned journal *Science Advances* reported a highly groundbreaking scientific research achievement. Professor Yao Baoli from the Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, together with Professor Olivier J. F. Martin's team from the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, has successfully developed Optical Tweezers Sectioning Microscopy (OTSM) through unremitting efforts. This technology is of extraordinary significance. It breaks through traditional limitations and realizes all-optical 3D imaging of suspended living cells. Not only can it conduct dynamic observation of living cells, but it also facilitates research on multicellular assembly. It can be said that Optical Tweezers Sectioning Microscopy provides an innovative tool for related biological applications and pushes biological research to a new height. ### Research Background In biological research, 3D imaging technology is a core tool for analyzing cell structures and dynamic processes. Cells are the basic unit of life, and their internal structures and dynamic changes hold the secrets of life activities. 3D imaging technology can present cell morphology, internal tissue distribution, and dynamic evolution at different stages from a three-dimensional perspective, providing key support for researchers to explore cellular physiological and pathological mechanisms and promoting the development of biological research. However, traditional optical methods have exposed obvious limitations in practical applications, mainly due to inherent flaws in their technical principles. Traditional optical methods rely on adhesion or mechanical fixation to achieve cell manipulation and scanning. This approach has many problems in operation, greatly restricting its application in cell research. - On one hand, traditional methods have extremely limited applicability to suspended cells. In organisms, many cells exist in a suspended state and play important roles in physiological activities. But traditional methods are difficult to effectively manipulate and scan these suspended cells, making it impossible for researchers to comprehensively and accurately observe their structures and dynamic changes. - On the other hand, adhesion or mechanical fixation may induce cellular stress responses. When cells are fixed by external forces, their internal physiological balance is disrupted, triggering a series of stress responses. These responses will interfere with the normal physiological state of cells, leading to deviations in observation results, which cannot truly reflect the natural state of cells. Therefore, developing non-contact all-optical 3D imaging technology to realize in-situ observation of living suspended cells has always been a key challenge in promoting basic biological research and application development. ### Technological Innovation The core design of the newly developed Optical Tweezers Sectioning Microscopy (OTSM) lies in its ingenious technical integration. With outstanding scientific wisdom, the research team organically combined holographic optical tweezers (HOT) with structured illumination microscopy (SIM). Holographic optical tweezers have strong trapping capabilities, while structured illumination microscopy excels in imaging. The combination of the two constructs an integrated system with both trapping and imaging functions. The basic idea of this technology has a clear logic and clear steps: 1. First, the research team used petal-shaped optical traps to achieve precise capture of multiple suspended living yeast cells. The unique design of the petal-shaped optical traps can generate a specific optical force field, stably fixing the suspended living yeast cells in a specific position, laying the foundation for subsequent imaging operations. 2. Then, axial scanning is used to complete full-volume imaging. In this process, the system synchronously collects three phase-shifted images at each depth. This acquisition method can obtain information about cells at different angles and positions, providing rich data support for subsequent high-resolution reconstruction. 3. After the images are collected, they are reconstructed by the OS-SIM algorithm. This algorithm can accurately process the collected images, remove noise and interference, thereby obtaining high-resolution sections. These sections can clearly show the internal structure and details of cells. 4. Finally, Optical Tweezers Sectioning Microscopy realizes non-contact high-fidelity 3D reconstruction without sample fixation. This means that researchers can comprehensively and accurately observe and analyze suspended living cells without destroying their natural state. ### Experimental Verification The researchers carefully selected 12 suspended living yeast cells as experimental subjects. Through precise manipulation of the system, these cells were orderly arranged into hexagonal, pentagonal, and circular structures. In this process, the system showed extremely high precision and stability. At the same time, the system achieved high-definition 3D imaging, completely presenting the all-optical process from cell capture to 3D reconstruction, providing clear and accurate data for subsequent research. OTSM technology is highly innovative, fundamentally breaking through the dependence of traditional biological imaging on static samples and mechanical scanning. Traditional biological imaging methods often require sample fixation and mechanical scanning, which not only limits the research on living suspended cells but also may affect the physiological state of cells. In contrast, OTSM technology gets rid of these constraints and realizes dynamic observation of living suspended cells. Professor Yao Baoli pointed out that this technology has promoted the integration of structured illumination microscopes and optical manipulation technology. This interdisciplinary integration has laid the foundation for the further integration of optical tweezers with other imaging technologies. The combination of different technologies can give full play to their respective advantages, providing researchers with more powerful research tools. In terms of application prospects, OTSM technology is expected to meet the needs of isotropic resolution, large field of view, and super-resolution imaging. In cell research, these needs are crucial for in-depth understanding of cell structure and function. The emergence of OTSM technology provides a new way to solve these problems. This breakthrough provides a new paradigm for dynamic research on living suspended cells. It has great application potential in cell biology, developmental biology, and bioengineering fields: in cell biology, it can be used to study cell growth, differentiation, and other processes; in developmental biology, it helps reveal the mysteries of embryonic development; in the field of bioengineering, it can promote the development of cell engineering and tissue engineering. Its future application results are worthy of our expectation.