Extended depth-of-field fluorescence microscope for stable imaging during random positioning machine running

Area of Science:

• Biophysics
• Microscopy
• Space Biology

Background:

• Simulating microgravity using a random positioning machine (RPM) is crucial for biodynamical studies.
• Real-time in vivo imaging during RPM operation is challenging due to rotational-induced jitter.
• Stable imaging is essential for observing cellular dynamics under simulated microgravity.

Purpose of the Study:

• To develop an extended depth-of-field fluorescence microscope (EDOFM) for stable imaging during RPM operation.
• To overcome the limitations of RPM-induced jitter for live sample imaging.
• To enhance the observation of biological processes in simulated microgravity environments.

Main Methods:

• Designed an EDOFM by inserting a glass plate to induce spherical aberration and extend depth-of-field (DOF).
• Integrated a low-numerical-aperture (NA) light stop to maintain imaging clarity.
• Validated the system using ZEMAX simulations and experimental tests with transgenic zebrafish larvae.

Main Results:

• Achieved over a 15-fold extension in DOF compared to conventional wide-field microscopy.
• Demonstrated superior imaging stability and signal capture during RPM operation.
• Successfully tracked blood cells in vivo in zebrafish larvae under both stationary and rotating RPM conditions.

Conclusions:

• The developed EDOFM provides stable, high-clarity imaging for live samples on an RPM.
• This technology significantly improves the ability to study microgravity effects on biological systems.
• The EDOFM system holds potential for broad applications in space biology and microgravity research.