Optically Accessible Microfluidic Flow Channels for Noninvasive High-Resolution Biofilm Imaging Using Lattice Light...

Area of Science:

• Microscopy
• Microfluidics
• Bacterial biofilms

Background:

• Long-term, high-resolution imaging is crucial for understanding cellular dynamics in bacterial biofilms.
• Lattice light sheet microscopy (LLSM) offers high spatial/temporal resolution and low phototoxicity but is incompatible with biofilm research due to its open-top design and water-immersion objectives.
• Existing LLSM setups pose challenges for studying pathogenic bacteria, including lens contamination and safety concerns.

Purpose of the Study:

• To adapt LLSM for long-term, high-resolution imaging of bacterial biofilms.
• To develop a method for studying pathogenic bacterial growth under controlled conditions.
• To overcome the limitations of current microscopy techniques in biofilm research.

Main Methods:

• Developed hermetically sealed, optically accessible microfluidic flow channels.
• Utilized a thin polymer film, matched to the refractive index of water, to create a liquid- and gas-tight seal on a 3D-printed channel.
• Integrated the microfluidic flow channels with LLSM for biofilm imaging.

Main Results:

• The developed microfluidic channels sustained bacterial biofilm growth for multiple days under controlled conditions.
• Negligible optical aberrations were achieved using refractive index-matched polymer films.
• Successfully recorded the growth of *S. oneidensis* MR-1 biofilms over several days at cellular resolution using LLSM without observable phototoxicity or photodamage.

Conclusions:

• The novel microfluidic flow channels enable LLSM compatibility with pathogenic bacterial biofilm studies.
• This approach facilitates long-term, high-resolution, and safe observation of biofilm dynamics at the cellular level.
• The technology opens new avenues for investigating bacterial behavior and interactions within biofilms.