Research On Human Red Blood Cell Based On Laser Tweezers Raman Spectroscopy Technology

Laser tweezers Raman spectroscopy ?LTRS? integrating optical tweezers with confocal Raman spectroscopy ensures the trapping, manipulation, measurement and biochemical analysis under physiological conditions for the single living cell analysis in suspension. In this paper, we described the construction and optimization of laser tweezers Raman spectroscopy system. Then the system was applied to the analysis of single living red blood cells. Combining the detection of red blood cell Raman spectrum with the multivariate mathematical statistical method, we aim to explore a new simple, rapid and nondestructive method for blood type identification and diabetes screening. The main research work is as follows:1. Construction and optimization of optical tweezers Raman spectroscopy system. We combined the basic principles of optical tweezers and Raman spectroscopy technology to design and build the laser tweezers Raman spectroscopy system. Then the LTRS system was applied to the detection of red blood cells ?RBC? Raman spectrum to test the performance of the system. Besides, combined with the test results, we further optimized the system so as to improve the resolution, stability and real-time monitoring capabilities of the system. After the optimization, the LTRS system built by ourselves achieved good spectral resolution, wavelength reproducibility and signal-to-noise ratio ?SNR?.2. Research on the detection of RBC blood group based on laser tweezers Raman spectroscopy system. We tested the Raman spectra of single living cell from 120 healthy subjects ?30 cases from each blood type? with different blood groups under physiological conditions. Based on the measured spectral data, we have carried on the multivariate statistical analysis to blood group by using two kinds of mathematical statistical models, including principal component analysis and linear discriminant analysis ?PCA-LDA? and partial least-squares discriminant analysis ?PLS-DA?. Classification results obtained from cross-validation of the LDA model based on the four LTRS spectral data sets of different groups demonstrated different diagnostic sensitivities and specificities:93.3% and 96.7% for A/O groups,83.3% and 80% for A/B groups,96.7% and 96.7% for O/B groups, respectively. And based on the analysis of PLS-DA method, we got the sensitivity ?83.3%, 93.3%,86.7% and 95.5%? and the specificity ?100%,100%,92.2% and 100%? for the four blood groups of A, O, B and AB blood type, respectively.3. Research on the RBC from diabetic patients using the laser tweezers Raman spectroscopy system. We have tested the Raman spectra of a single cell from 30 cases of diabetic patients and 30 cases of healthy red blood cells under physiological conditions by using optical tweezers Raman spectroscopy system. Based on the measured spectral data, we analyzed the spectral data of RBC in patients with diabetes mellitus and healthy subjects by using the method of principal component analysis combining with linear discriminant analysis ?PCA-LDA?. As the analysis results we got, the sensitivity and specificity of the diagnosis of diabetes were 100% and 93.3%, respectively. The accuracy rate was 99.8%. In addition, based on the different Raman spectral line of RBC we measured between healthy subjects and diabetic patients,676cm^-1 peaks corresponding to methionine molecule might be the characterization of the RBC composition and structural differences between healthy subjects and diabetic patients and, while 756-791cm^-1 may be characterized as the glycosylation of hemoglobin, which may be the diagnostic basis for diabetes.