New Fluorescence Microscope Features Fast Super-Res Imaging with Wide Field of View

Researchers from Bielefeld University have developed a fluorescence microscope that uses structured illumination for fast super-resolution imaging over a wide field of view. The new microscope was designed to image multiple living cells simultaneously with a very high resolution to study the effects of various drugs and mixtures of drugs on the body.

In a paper published in Optics Express, the researchers describe their new microscope that uses optical fiber delivery of excitation light to enable very high image quality over a very large field of view with multicolor and high-speed capability. They show that the instrument can be used to image liver cells, achieving a field of view up to 150 x 150 μm² and imaging rates up to 44 Hz while maintaining a spatiotemporal resolution of less than 100 nm.

“With this new microscope, individual drug combinations can be tested on isolated cells and then imaged with super-resolution to observe dynamics of cell membrane features or organelles,” said first author Henning Ortkrass. “The large field of view can provide statistical information about the cell response, which could be used to improve personalized healthcare. Thanks to the system’s potentially small size, it might also be useful for clinical applications where high resolution is important.”

The new microscope is based on super-resolved structured illumination microscopy (SR-SIM), which uses a structured pattern of light to excite fluorescence in a sample and achieve a spatial resolution beyond the diffraction limit of light. SR-SIM is particularly well suited for live cell imaging because it uses low-power excitation that doesn’t harm the sample while producing highly detailed images.

To achieve high resolution across a wide field of view, the new microscope reconstructs super-resolved images from a set of raw images. These raw images are acquired by using a set of six optical fibers to illuminate the sample with a sinusoidal striped pattern that is shifted and rotated to gain extra information. This creates a two-fold resolution improvement while still achieving fast imaging and being compatible with live cell imaging.