yijia wang, yuquan zhang, shiwu zhang, zhenying zhao, Changjun Min, jun liu and Xiaocong Yuan
The detection of cellular responses to drugs is important for biomedical research, but there is a lack of convenient label-free methods to analyze responses at the single cell level. The refractive index is a typical biophysical parameter reflecting cell status. An optical tweezers system was established to measure trapping efficiency, which relates to the refractive index. The response of two cancer cell lines and their paclitaxel resistant counterparts were measured using optical tweezers. Cyclin B1 expression, polymerized tubulin and caspase-3 activation were measured, compared and associated with the trapping efficiency. The results show that trapping efficiency declined sharply when caspase-3 was activated. These results suggest that optical tweezers can be used as an auxiliary method to analyze cellular responses to anti-tumor drugs.
DOI
Showing posts with label Analytical Methods. Show all posts
Showing posts with label Analytical Methods. Show all posts
Tuesday, April 12, 2016
Tuesday, August 18, 2015
Single-cell analysis based on lab on a chip fluidic system
Alireza Valizadeh and Ahmad Yari Khosroushahi
The combination of nano/microfabrication-based technologies with cell biology has laid the foundation for facilitating the spatiotemporal analysis of single cells under well-defined physiologically relevant conditions. This combined technology allows so far unachievable insights into simultaneous characterization and manipulation of cells. Nano/microfluidic technology provides cost-effective, integrated, and high-throughput systems that are promising substitutes for conventional biological laboratory methods going from fundamental research to point-of-care diagnosis. This inscription reviews the latest progresses regarding cell manipulation methods based on; dielectrophoretic, electrophoresis, optical, acoustical, encaging, hydrodynamic, magnetite, centrifugal cell trapping/sorting, and cell characterization based on mechanical, electrical, biochemical, and optical methods using fluidic systems.
DOI
The combination of nano/microfabrication-based technologies with cell biology has laid the foundation for facilitating the spatiotemporal analysis of single cells under well-defined physiologically relevant conditions. This combined technology allows so far unachievable insights into simultaneous characterization and manipulation of cells. Nano/microfluidic technology provides cost-effective, integrated, and high-throughput systems that are promising substitutes for conventional biological laboratory methods going from fundamental research to point-of-care diagnosis. This inscription reviews the latest progresses regarding cell manipulation methods based on; dielectrophoretic, electrophoresis, optical, acoustical, encaging, hydrodynamic, magnetite, centrifugal cell trapping/sorting, and cell characterization based on mechanical, electrical, biochemical, and optical methods using fluidic systems.
DOI
Thursday, October 3, 2013
Fast Detection of Saxitoxin Using Laser Tweezers Surface Enhanced Raman Spectroscopy
Qiyong Huai, Chunlei Gao, Jinlai Miao, huilu yao and Zongling Wang
Saxitoxin (STX) is a potent marine biotoxin which can cause paralytic shellfish poisoning when consumed. With the development of research, STX has become more and more important in red tide detection, medical research, food safety and warfare agent application. However, new methods for the fast analysis of STX are required. In this study, we used laser optical tweezers Raman spectroscopy (LTRS) combined with surface-enhanced Raman scattering (SERS) to detect STX. Very strong intensity and sharp Raman peaks were achieved. The spectra were obtained at 2 seconds without accumulations. Tentative vibrational mode assignments of the observed peaks for SERS spectra of STX are described. The detection limit and the minimum quantitative limit of this method were 2 nM and 16 nM, respectively. This study supports LTRS - SERS as a new fast, convenient analytical method for STX and other toxicants and pollutants in the environment.
DOI
Saxitoxin (STX) is a potent marine biotoxin which can cause paralytic shellfish poisoning when consumed. With the development of research, STX has become more and more important in red tide detection, medical research, food safety and warfare agent application. However, new methods for the fast analysis of STX are required. In this study, we used laser optical tweezers Raman spectroscopy (LTRS) combined with surface-enhanced Raman scattering (SERS) to detect STX. Very strong intensity and sharp Raman peaks were achieved. The spectra were obtained at 2 seconds without accumulations. Tentative vibrational mode assignments of the observed peaks for SERS spectra of STX are described. The detection limit and the minimum quantitative limit of this method were 2 nM and 16 nM, respectively. This study supports LTRS - SERS as a new fast, convenient analytical method for STX and other toxicants and pollutants in the environment.
DOI
Monday, March 18, 2013
Analytical Techniques for Single-Liposome Characterization
Xiaomei Yan , Chaoxing Chen , Shaobin Zhu , Tianxun Huang and Shuo Wang
Liposomes or phospholipid vesicles are one of the most versatile nanoparticles used to convey drugs, vaccines, genes, enzymes, or other substances to target cells and as a model to mimic biological membranes. To fulfill their roles in drug delivery and biotechnology, physical and chemical properties of liposomes, such as size, shape, chemical composition, lamellarity, encapsulation efficiency of cargo molecules, and the density of proteins reconstituted in the membrane need to be characterized to ensure a reproducible preparation of vesicles. Compared to bulk analysis, techniques focusing on the individual analysis of liposomes can reveal the heterogeneity that is otherwise masked by ensemble averaging. Herein, we review the recent advancement in techniques for single-liposome characterization.
DOI
Liposomes or phospholipid vesicles are one of the most versatile nanoparticles used to convey drugs, vaccines, genes, enzymes, or other substances to target cells and as a model to mimic biological membranes. To fulfill their roles in drug delivery and biotechnology, physical and chemical properties of liposomes, such as size, shape, chemical composition, lamellarity, encapsulation efficiency of cargo molecules, and the density of proteins reconstituted in the membrane need to be characterized to ensure a reproducible preparation of vesicles. Compared to bulk analysis, techniques focusing on the individual analysis of liposomes can reveal the heterogeneity that is otherwise masked by ensemble averaging. Herein, we review the recent advancement in techniques for single-liposome characterization.
DOI
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