Mapping blood biochemistry by Raman spectroscopy at the cellular level

Area of Science:

• Biochemistry
• Cellular Biology
• Spectroscopy

Background:

• Cellular biochemistry and environment influence cellular function.
• Blood cell analysis is crucial for diagnostics.
• Raman spectroscopy offers label-free molecular information.

Purpose of the Study:

• To demonstrate Raman difference imaging for in vivo cellular biochemistry analysis.
• To establish Raman imaging as a diagnostic tool for blood biochemistry at the cellular level.
• To investigate hemoglobin distribution in healthy and unhealthy blood cells.

Main Methods:

• Utilizing Raman difference imaging for sub-cellular biochemical analysis.
• Examining Raman microscopic images of hemoglobin distribution in discocytes and echinocytes.
• Employing pre-calculated, accurate pre-resonant Raman tensors for scattering intensity interpretation.
• Performing theoretical calculations for heme models (oxy, deoxy, met) benchmarked against experimental spectra.

Main Results:

• Raman difference imaging provides insights into cellular biochemistry based on sub-cellular dimensions and environment.
• The approach serves as a sensitive diagnostic for blood biochemistry at the cellular level.
• Distinct hemoglobin distributions were observed in healthy (discocyte) and unhealthy (echinocyte) blood cells.
• Theoretical calculations accurately assigned electronic transitions responsible for blood color, primarily ligand-to-metal charge transfer.

Conclusions:

• Raman difference imaging is a powerful tool for in vivo cellular biochemistry and blood analysis.
• This technique enables sensitive diagnostics at the cellular level, differentiating between healthy and unhealthy blood cells.
• The study provides a theoretical framework for interpreting Raman spectra of hemoglobins and understanding blood coloration.