Confocal

Seeing is believing, a well-known phrase holds excellent significance in science and in this context, optical microscopy is an important, widely accepted and non-invasive tool for direct visualization of microstructures of materials, biological specimens, and more. Confocal microscopy is a powerful optical imaging technique that facilitates the acquisition of high-resolution and high contrast images of samples when compared to conventional wide-field microscopy. This is achieved by employing a pinhole in front of the detector that spatially filters out-of-focus light from above and below the focal plane.

Confocal microscopy can provide better depth penetration and resolution in the axial direction through appropriate optical sectioning, thereby enhancing three-dimensional visualization, particularly useful for observing thick tissues like skin tissue, brain slices and plant cell walls, morphology and growth of spheroids and organoids, sub cellular localization of drug molecules and biological markers, and colocalization studies. It enables researchers to distinguish between autofluorescence and real fluorescence signals at the time of experiment directly, which is particularly helpful when imaging plant tissues, fungal or algae samples. Confocal microscopy allows live cell imaging, making it possible to observe dynamic processes such as cell division, migration, membrane dynamics and signal transduction.

Using FRET, FRAP, FCS, FLIM and FLIP, one can quantify the dynamics of interaction and diffusion coefficients of the components in the sample. The technique is helpful for examination of photophysical properties of synthesized dyes and nanomaterials like quantum dots, nanowires, and nanoparticles. With recent advancements, using super-resolution modalities, nanoscale organization and substructures of biomolecules can also be visualized.