Label-free intracellular transport measured by spatial light interference microscopy.

Area of Science:

• Cell biology
• Microscopy techniques
• Biophysics

Background:

• Traditional microscopy methods like differential interference contrast (DIC) and fluorescence microscopy face limitations such as gradient artifacts, photobleaching, and phototoxicity.
• Observing dynamic processes within living cells, particularly the movement of organelles and vesicles, requires advanced imaging techniques that overcome these challenges.

Purpose of the Study:

• To introduce and demonstrate Laplace phase microscopy, a novel label-free imaging technique.
• To showcase the capability of Laplace phase microscopy in revealing high-resolution cellular structures and tracking subcellular components in living cells.

Main Methods:

• Application of the Laplace operator to speckle-free quantitative phase images of cells.
• Utilizing Laplace phase microscopy for label-free imaging and tracking of cellular components.
• Demonstration in cardiomyocytes and hippocampal neurons to track organelles and vesicles, respectively.

Main Results:

• Laplace phase microscopy provides unprecedented detail in cell structure, free from DIC's gradient artifacts and fluorescence microscopy's phototoxicity.
• The method successfully tracked organelles in cardiomyocytes and vesicles in neuronal processes.
• Achieved label-free diffusion measurements of organelles in cardiomyocytes and vesicles in hippocampal neurons.

Conclusions:

• Laplace phase microscopy is an efficient and versatile tool for high-resolution, label-free imaging of living cells.
• This technique overcomes major limitations of existing microscopy methods, enabling detailed observation of subcellular dynamics.
• It represents a significant advancement for studying organelle and vesicle transport in various cell types.