CH2-Symmetric/CH2-Antisymmetric Stretch Ratio Sensor for Cell Analysis

Here we report on a novel infrared sensor system for measuring the CH2-symmetric/CH2-antisymmetric stretch ratio of cell samples. Based on IR absorbance spectra of healthy and malignant breast [1], blood [2] and brain [3] cells found in literature we hypothesized the possibility of disease stage cell discrimination by only comparing a few absorbance peaks in the lipid absorbance wavelength region between 3 and 4 μm. By comparing the lipid CH2-symmetric and CH2antisymmetric stretch ratios (with baseline correction and normalization) of three defined epithelial kidney cell lines, healthy MDCK and carcinoma A-498 and Caki-1 with the developed sensor, significant stretch ratio differences have been found between healthy and tumor cell types (and even between the two tumor types). The developed LED-photodiode based infrared absorbance sensor could be used for quick prescreening of biopsy samples which, compared to labeling and staining techniques, does not require highly trained personnel and is much cheaper than liquid nitrogen cooled FTIR spectroscopes. Keywords— Infrared absorbance sensor, Label-Free, Cell analysis