A new dimension for cell identification by FTIR spectroscopy: depth profiling in attenuated total reflection.

Area of Science:

• Biophysics
• Spectroscopy
• Cancer Research

Background:

• Multidrug resistance (MDR) is a significant challenge in cancer chemotherapy, characterized by cell resistance to various drugs.
• Previous studies identified differences in infrared spectra between K562 multiresistant leukemia cells and sensitive wild-type K562 cells.

Purpose of the Study:

• To investigate the differences between K562 multiresistant and sensitive cells by modulating infrared penetration depth.
• To enhance discrimination between cell types by optimizing the infrared beam's focus.

Main Methods:

• Utilized Attenuated Total Reflectance Fourier Transform Infrared (ATR FTIR) spectroscopy.
• Controlled infrared penetration depth by adjusting the incident angle.
• Analyzed depth-dependent spectral differences between cell lines.

Main Results:

• Modulating the incident angle allowed for depth profiling of K562 cells.
• Focusing the infrared beam on specific depths improved the discrimination between multiresistant and sensitive cells.
• Difference spectra revealed depth-dependent variations between the cell lines.

Conclusions:

• Depth profiling using ATR FTIR can enhance the differentiation of multidrug-resistant cells.
• The depth profile of spectral differences may help localize biochemical changes associated with multidrug resistance phenotype.