A mercury arc lamp-based multi-color confocal real time imaging system for cellular structure and function.

Area of Science:

• Biophysics
• Cell Biology
• Microscopy

Background:

• Nipkow disk confocal microscopy offers high spatial and temporal resolution for fluorescent imaging.
• Conventional systems using lasers restrict fluorophore choice due to limited excitation lines.
• Existing methods necessitate specific laser wavelengths, limiting experimental flexibility.

Purpose of the Study:

• To develop an alternative illumination system for Nipkow disk confocal microscopy.
• To overcome the limitations of laser-based excitation sources.
• To enable broader fluorophore compatibility and advanced live-cell imaging.

Main Methods:

• A mercury arc lamp was used as the excitation light source.
• Scrambled, homogeneous light was generated by passing light through a multi-mode optical fiber.
• The system was integrated with a Nipkow spinning disk confocal unit (Yokogawa CSU10).

Main Results:

• The developed system provides incoherent light with continuous wavelengths.
• This enables the observation of a wide range of fluorophores.
• High-speed imaging (up to 100 Hz) of intracellular Ca(2+) propagation was achieved.
• Multi-color imaging of Ca(2+) and PKC-gamma dynamics in living cells was demonstrated.

Conclusions:

• The novel illumination system overcomes laser restrictions in Nipkow disk confocal microscopy.
• It facilitates the observation of diverse fluorophores and advanced live-cell dynamics.
• This approach enhances the versatility and applicability of spinning disk confocal imaging.