Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by the diffraction of light. In the context of imaging, it is a set of techniques and algorithms that aim to achieve higher resolution images than what is traditionally possible using standard imaging systems. In conventional optical microscopy, the resolution is limited by the diffraction of light, a phenomenon described by Ernst Abbe's diffraction limit. This limit sets a fundamental constraint on the ability to resolve details in an image, especially when imaging small structures.
Superresolution techniques overcome this limitation, allowing scientists and researchers to visualize finer details in biological samples, materials, or other objects. There are several superresolution techniques, and some of the prominent ones include:
Structured illumination microscopy (SIM): SIM involves illuminating the sample with a patterned light, and by analyzing the resulting images, higher-resolution information can be extracted.
Stimulated emission depletion microscopy (STED): STED uses a pair of laser beams, one for excitation and another for de-excitation, to control the fluorescence emission and achieve a smaller effective point spread function.
Single-molecule localization microscopy (SMLM): Techniques like PALM (photoactivated localization microscopy) and STORM (stochastic optical reconstruction microscopy) rely on the precise localization of individual fluorophores to build up a higher resolution image.
Expansion microscopy: This technique involves physically expanding the sample before imaging, allowing for higher resolution with conventional microscopes.
Superresolution techniques have revolutionized biological and materials imaging, enabling scientists to study cellular structures and molecular interactions with unprecedented detail. These methods play a crucial role in advancing various fields, including cell biology, neuroscience, and materials science.