A widefield fluorescence microscope with a linear image sensor for image cytometry of biospecimens: Considerations...

Area of Science:

• Biomedical Engineering
• Optical Microscopy
• Image Cytometry

Background:

• Linear image sensors are crucial for continuous imaging of dynamic processes.
• Widefield fluorescence microscopy is a key technique in biological research.
• Image cytometry requires high-resolution imaging of cellular structures.

Purpose of the Study:

• To develop and validate a widefield fluorescence microscope utilizing a linear image sensor for imaging translating objects.
• To establish a system capable of high-quality image cytometry for biological samples.
• To ensure accurate aspect ratio preservation for quantitative analysis of microscopic images.

Main Methods:

• Characterization of a microfluidic chamber with a calibration curve for volumetric pump rates.
• Imaging of fluorescent polystyrene spheres on a motorized translation stage to optimize linear translation speed and line exposure.
• Acquisition and quality control of images from stained whole blood and oral squamous cells using proflavine hemisulfate.

Main Results:

• Successful imaging of fluorescent beads in a microfluidic chamber at 16 μl/min with a 150 μs line exposure, achieving a 40 dB signal-to-background ratio.
• High-resolution imaging of leukocyte morphology in whole blood with a 0.31 μm/pixel resolution.
• Quantification of subcellular features in oral squamous cells, including an average nuclear-to-cytoplasmic ratio of 0.03.

Conclusions:

• The developed widefield fluorescence microscope with a linear image sensor is effective for image cytometry of translating biological specimens.
• The system demonstrates capability for high-resolution imaging and quantitative analysis of cellular morphology and subcellular features.
• Accurate aspect ratio preservation is critical and achievable for reliable microscopic image data.