Two-Color Stimulated Raman Scattering Imaging of Mouse Brain Tissue

Take a mouse brain slice inside a chamber on a slide and place it under a microscope with a stimulated Raman scattering, or SRS, imaging system.

Focus two synchronized laser beams, known as the pump and Stokes beams, onto the tissue.

The energy difference between these beams matches the vibrational frequency of specific molecules, inducing molecular vibrations.

Excite the tissue lipids and proteins, having unique molecular vibrations, using distinct frequency pairs of the synchronized beams.

The excitation facilitates energy transfer between the beams, reducing the pump beam intensity while increasing the Stokes beam intensity.

The relative intensity change is detected as an SRS signal that helps identify the molecules.

A photodetector collects the combined SRS signals from the sample.

Assign the lipid and protein signals separate colors, creating a two-colored image, to identify the proteins and lipids in the brain tissue.

Place a beam sampler in the stokes beam path to pick up 10% of the beam. And send it to a fast photodiode to detect the 8 megahertz pulse train. Take one of the outputs of the fanout buffer and filter it with a bandpass filter to obtain the 20 megahertz sinusoidal wav