Quantitative determination of functional thiol groups on intact cell surfaces by resonance Raman spectroscopy

Area of Science:

• Biophysical Chemistry
• Spectroscopy
• Cell Biology

Background:

• Quantifying membrane thiols in erythrocytes is crucial for understanding cell function and health.
• Existing methods may lack sensitivity or be complicated by cell lysis.
• In situ analysis of thiol populations in viable cells presents a significant challenge.

Purpose of the Study:

• To develop and validate a novel spectroscopic method for quantifying membrane thiol populations in viable erythrocytes.
• To utilize the sensitivity and selectivity of resonance Raman and electronic spectroscopy for this purpose.
• To establish a method that can be performed in situ and account for potential lysis.

Main Methods:

• Employing resonance Raman spectroscopy combined with electronic spectroscopy.
• Utilizing the thiol-disulfide reaction of Ellman's reagent (5,5'-dithio-bis-2-nitrobenzoic acid).
• Developing a method for continuous monitoring of lysis with correction capabilities and internal calibration.

Main Results:

• Demonstrated the ability to quantify membrane thiol population in situ in viable erythrocytes.
• The technique offers high sensitivity and selectivity.
• Continuous monitoring of lysis is feasible, with corrections for interference and internal calibration via reagent signal ratio.

Conclusions:

• Resonance Raman and electronic spectroscopy provide a powerful tool for in situ quantification of erythrocyte membrane thiols.
• The developed method is sensitive, selective, and robust against lysis.
• This technique offers a significant advancement for studying thiol-based cellular processes.