A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (
Erythrocyte Deformability ; Erythrocytes ; Humans ; Microfluidics ; Optical Tweezers ; Viscosity

In order to understand biological phenomena accurately, single molecule techniques using a physical research approach to molecular interactions have been developed, and are now widely being used to study complex biological processes. In this review, we discuss some of the single molecule methods which are composed of two major parts: single molecule spectroscopy and manipulation. In particular, we explain how these techniques work and introduce the current research which uses them. Finally, we present the oral biology research using the single molecule methods.
Biological Phenomena ; Biological Processes ; Biology ; Methods ; Molecular Biology ; Optical Tweezers ; Spectrum Analysis

Laser tweezers Raman spectroscopy (LTRS) system is a combination of spectroscopy and laser tweezers; It is a new method of studying cells; It can trap single living cell and make Raman spectrum of single living cell. From the positions, intensities, and line widths of the Raman peaks in the spectra, we can get useful information about composition, structure and interactions of complexes inside the living cells. External agents may change cell's physiological state and this changed information can also be got from Raman spectra. This article is a study of Raman spectra of human red blood cell (RBC) affected by different intensity direct current (DC); from the result, distinct change of Raman spectra of RBC have been got. These changes characterize the changes of the internal information of the cells. This article give some academic reference of physical therapy using DC in the level of molecule.
Electricity ; Erythrocytes ; cytology ; physiology ; Humans ; Lasers ; Optical Tweezers ; Spectrum Analysis, Raman ; methods

Red blood cell (RBC) dysfunction is often associated with a pathological intervention, and it has been proposed as a critical risk factor for certain lethal diseases. Examining the cell viability of RBCs under various physiological conditions is essential and of importance for precise diagnosis and drug discovery in the field of medicine and pharmacy. In this paper, we report a new analytical method that employs dielectrophoretic (DEP) force measurements in absolute units to assess the viability, and potentially the functionality of RBCs. We precisely quantify the frequency-dependent DEP forces of the RBCs by using a micro-electrode embedded chip combined with optical tweezers. DEP characteristics are known to be well-correlated with the viability of biological cells, and DEP forces are measured in both fresh and long-term stored RBCs to investigate the effect that the storage period has on the cell viability. Moreover, we investigate the DEP behavior of RBCs when exposed to oxidative stress and verify whether EDTA protects the RBCs from an oxidant. From the experiments, it is found that the fresh RBCs without oxidative stress display very high DEP forces over the entire frequency range, exhibiting two cutoff frequencies. However, both the RBCs stored for the long-term period and exposed to oxidative stress reveals that there exist no significant DEP forces over the frequency range. The results indicate that the DEP forces can serve as a useful parameter to verify whether the RBCs in certain blood are fresh and not exposed to oxidative stress. Therefore, it is believed that our system can be applied to a diagnostic system to monitor the cell viability of the RBCs or other types of cells.
Cell Survival ; Diagnosis ; Drug Discovery ; Edetic Acid ; Erythrocytes* ; Methods ; Microfluidics* ; Optical Tweezers* ; Oxidative Stress* ; Pharmacy ; Risk Factors