Compensating the Meniscus Effect in Phase Contrast Microscopy Using an LCD for Adaptive Condenser Annulus Shifting.

Area of Science:

• Biomedical Imaging
• Microscopy Technology
• Cell Culture Techniques

Background:

• The meniscus effect in cell culture vessels limits phase contrast microscopy.
• Standard condenser annuli in microtiter plates (MTPs) are static and cannot compensate for this effect.
• This limitation reduces the observable area for cellular analysis.

Purpose of the Study:

• To develop a method for compensating the meniscus effect in MTPs using phase contrast microscopy.
• To increase the observable area in MTPs by adapting the condenser annulus.
• To improve the reliability and scope of cell imaging in microtiter plate formats.

Main Methods:

• Replaced the static condenser annulus with a transparent liquid crystal display (LCD) capable of adaptive annulus shifting.
• Developed image analysis using Bertrand lens images to determine annulus and phase ring misalignment.
• Implemented a linear regression model to translate image analysis data into LCD settings for optimal alignment.
• Utilized a background brightness algorithm to reliably assess phase contrast conditions.

Main Results:

• Achieved an 8.3-fold increase in the phase contrast observable area.
• Increased the phase contrast area in 24-well MTPs from 5.0% to 41.9% at 10× magnification.
• Demonstrated effective compensation for meniscus-induced refraction across MTP wells, excluding edges.

Conclusions:

• The adaptive LCD annulus method effectively compensates for the meniscus effect in MTPs.
• This technique substantially expands the usable area for phase contrast microscopy in cell culture.
• The proposed approach offers a significant advancement for high-throughput cell-based assays requiring phase contrast imaging.