Hadamard transform spectral microscopy for single cell imaging using organic and quantum dot fluorescent probes

Area of Science:

• Biomedical Optics
• Microscopy
• Spectroscopy

Background:

• Traditional microscopy often lacks spectral resolution for detailed cellular analysis.
• Advanced imaging techniques are needed to visualize subcellular structures and processes with high sensitivity.

Purpose of the Study:

• To develop and validate a Hadamard transform fluorescence spectral imaging microscopy system.
• To demonstrate its capability for high-resolution, multi-spectral imaging in biological samples.
• To explore its potential in identifying cellular apoptosis and quantifying cancer biomarkers.

Main Methods:

• Utilized a movable one-dimensional Hadamard mask for signal encoding.
• Employed a linear charge-coupled device (CCD) for detecting encoded spectral image signals.
• Achieved four-dimensional imaging: X, Y spatial coordinates, Z fluorescence intensity, and lambda wavelength (or time).

Main Results:

• Demonstrated high spectral resolving power (0.3 nm) and imaging resolution (up to 511 x 512).
• Successfully identified apoptosis in fibroblast cells using spectral evidence.
• Visualized and quantitatively measured subcellular proteins (HER-2, ER) in breast cancer tissue using dual-color fluorescence imaging with quantum dots.

Conclusions:

• The Hadamard imaging system offers high spectral and spatial resolution for analyzing tiny samples.
• It enables accurate identification of cellular apoptosis and visualization of cancer biomarkers.
• This technology shows significant potential as a valuable tool in biomedical research and diagnostics.