Figure 1.

A) Reference raman spectrum acquired from a single point in mouse meibomian gland. For SRS imaging, two laser beams at different optical frequencies were utilized to probe the vibrational resonance of the CH₂ bending (1440 cm⁻¹) and amide-I (1650 cm⁻¹) modes, representing the lipid and protein markers, respectively. Laser beams were scanned through the tissue section via an inverted microscope. Resulting images at 1440 cm⁻¹ and 1650 cm⁻¹ modes are shown in panel B and C, respectively. Protein-to-lipid ratios (P/L) were calculated by dividing the pixel intensities at 1650 cm⁻¹ with intensities at 1440 cm⁻¹. Image width in Panel B and C is 353.5 µm.