Researchers from the Transdimensional Life Imaging Division of the Institute for Open and Transdisciplinary Research Initiatives at Osaka University created an optical imaging system that can capture an unprecedented number of cells in a single image. The work provides a valuable tool for the simultaneous observation of centimeter-scale dynamics of multicellular populations with micrometer resolution to see the functions of individual cells. “Conventional biological microscopes can observe at most 1000 cells, with a field of view limited to a few millimeters. Our setup uses machine vision powered by a high-pixel camera with a macro lens,” Taro Ichimura, the research paper’s first author, said. A multicolor image of a mouse brain slice with two regions indicated by light blue squares, namely, the cerebral cortex (A) and the hippocampus (B). These are displayed in the whole-brain image (left) and digitally magnified 5× (middle). The local regions of light blue squares in the 5× images are further digitally magnified 5× (right). Red, green, and blue represent the fluorescence due to a red fluorescent protein expression in excitatory projection neurons, a green fluorescent protein expression in inhibitory interneurons, and Hoechst 33342 attached to nuclear DNA, respectively. Courtesy of T. Ichimura et al., Scientific Reports. The team built the optical imaging system with a 120-MP camera and a telecentric macro lens. This provided a much larger field of view than conventional microscopes, up to 1.5 × 1 cm, while still resolving individual cells and the interactions between them that characterize the population. The team termed the technology “trans-scale scope,” which signifies that the technology can be applied to imaging from the micrometer scale to the centimeter scale. “As a technological singularity for a powerful cell measurement, our trans-scale scope system AMATERAS is expected to contribute to a wide range of applications, from basic research for understanding the operating mechanism of multicellular systems, to medical applications such as the quality control of artificial cell sheets,” senior author Takeharu Nagai said. AMATERAS (a multiscale/modal analytical tool for every rare activity in singularity) was tested by dynamically imaging calcium ions in cultured cells, and it successfully detected anomalies that occurred in fewer than 0.01% of specimens. The work could accelerate research in a wide range of fields that deal with large cell populations, such as neuroscience, oncology, and immunology. The research was published in Scientific Reports (www.doi.org/10.1038/s41598-021-95930-7).
