Note: in vivo pH imaging system using luminescent indicator and color camera

Area of Science:

• Microscopy and Imaging
• Biophysical Chemistry
• Plant Cell Biology

Background:

• Accurate in vivo pH measurement is crucial for understanding cellular processes.
• Existing methods often lack spatial resolution or quantitative accuracy.
• Correlating pH distribution with cellular structure requires integrated imaging techniques.

Purpose of the Study:

• To develop a microscopic system capable of simultaneous in vivo luminescent and color imaging for pH determination.
• To enable quantitative pH mapping overlaid with structural information.
• To demonstrate the system's application in plant epidermal cells.

Main Methods:

• A digital color camera was employed to capture both luminescent and color images.
• HPTS (8-hydroxypyrene-1,3,6-trisulfonate) was utilized as a luminescent pH indicator.
• The excitation-ratio method, using filter units within the microscope, was applied to acquire two luminescent images for pH calculation, followed by a priori calibration.

Main Results:

• The developed system successfully captured luminescent and color images simultaneously.
• Quantitative in vivo pH distribution was obtained.
• Structural information from color imaging was overlaid onto pH maps, enabling correlation.

Conclusions:

• The novel microscopic system effectively provides quantitative in vivo pH imaging.
• The integration of luminescent and color imaging allows for structural-pH correlation.
• The system is applicable to biological specimens, as shown with Lactuca Sativa L epidermal cells.