Scientists have demonstrated a new way to precisely target cells by distinguishing them from neighboring cells that look quite similar. Even cells that become cancerous may differ from their healthy neighbors in only a few subtle ways. A central challenge in the treatment of cancer and many ... more
Progress toward Personalized Medicine
Microfluidic chip for analysis of single cells
A few little cells that are different from the rest can have a big effect. For example, individual cancer cells may be resistant to a specific chemotherapy—causing a relapse in a patient who would otherwise be cured. In the journal Angewandte Chemie, scientists have now introduced a microfluidics-based chip for the manipulation and subsequent nucleic-acid analysis of individual cells. The technique uses local electric fields to highly efficiently “trap” the cells (dielectrophoresis).
Molecular analyses of individual cells are necessary to better understand the role of heterogenous cell populations in the development of diseases and to develop effective therapies for personalized medicine. Identifying individual cells in a mass of other cells is an enormous challenge in diagnostic medicine. The cells must be sorted, held, transferred into another container with an extremely small volume (< 1 µL) and then must undergo molecular analysis. Conventional methods are usually very time consuming and complex, as well as unreliable and inefficient. They can also compromise the viability of the cells, require large sample volumes, have a high risk of contamination, and/or require expensive instruments.
Scientists from the University of Washington (Seattle, USA), Iowa State University (Ames, USA), and Fred Hutchinson Cancer Research Center (Seattle, USA) have used microfluidic technology to overcome these problems. All of the necessary steps occur reliably on a specially developed microchip using minimal amounts of solvent and without requiring the cells to be marked. In contrast to conventional microfluidic chips, this one requires neither complex fabrication technology nor components like valves or agitators.
The Self-Digitization Dielectrophoretic (SD-DEP) chip is about the size of a coin and has two parallel microchannels (50 µm deep x 35 µm wide x 3.2 cm long) connected by numerous tiny little chambers. The openings of the microchannels are only 15 µm wide. A thin electrode is stretched along the length of the channels. The channels and chambers are filled with a buffer, an alternating voltage is applied, and the sample is added to one of the microchannels. The team headed by Robbyn K. Anand and Daniel T. Chiu used leukemia cells in their experiments.
Local maxima of the electric field occur at the narrow entrances to the chambers. Cells that enter the chambers are “trapped”. Because the dimensions of the entrance are similar to the average size of a cell, only a single cell can be trapped by each chamber entrance. When the alternating current is switched off and the flow rate is increased by injection of the reagents required for subsequent analysis, the cells are washed into the chambers. An oil is then added to seal the chambers. The cells are then dissolved, and the nucleic acids are released and multiplied and can be identified as leukemia cells by a marker gene.
In future studies, the researchers hope to use the chip to determine the distribution of genetic mutations that are related to resistance in leukemia cells and thus may cause relapses.
- personalized medicine
- single cell analysis
- microfluidic chips
- nucleic acid analysis
Researchers studying Alzheimer's disease have created an approach to classify patients with Alzheimer's disease, a finding that may open the door for personalized treatments. "Alzheimer's, like breast cancer, is not one disease," said lead author Shubhabrata Mukherjee, research assistant pr ... more
University of Washington engineers have turned tissue paper – similar to toilet tissue – into a new kind of wearable sensor that can detect a pulse, a blink of an eye and other human movement. The sensor is light, flexible and inexpensive, with potential applications in health care, enterta ... more
Researchers have developed new nanoscale technology to image and measure more of the stresses and strains on materials under high pressures. As the researchers reported in the journal Science, that matters because, "Pressure alters the physical, chemical and electronic properties of matter. ... more
Using the physics equivalent of the strobe photography that captures every twitch of a cheetah in full sprint, researchers have used ultrafast spectroscopy to visualize electrons interacting as a hidden state of matter in a superconductive alloy. It takes intense, single-cycle pulses of pho ... more
Using a new and super-sensitive instrument, researchers have discovered where a protein binds to plant cell walls, a process that loosens the cell walls and makes it possible for plants to grow. Researchers say the discovery could one day lead to bigger harvests of biomass for renewable ene ... more
Scientists can monitor biomolecular processes in live tissue by noninvasive optical methods, such as fluorescence imaging. However, the fluorescent dyes used for that purpose are often rather unstable, and photobleaching, lack of specificity, and poor pharmacokinetics are recurrent issues. ... more
In the treatment of tumors, microenvironment plays an important role. It often contains immune cells that are so changed that they promote tumor growth. In the journal Angewandte Chemie, scientists have introduced a method by which cell samples from tumors and their surroundings can rapidly ... more
A good indicator of dysregulation in live cells is a change in their RNA expression. MicroRNA (miRNA), a special type of RNA, is considered a biomarker for carcinogenic cells. A team of scientists from China has found a way to amplify miRNA in live tumor cells for bioimaging. As they report ... more
- 1Detect neurodegenerative diseases such as Alzheimer's by a simple eye scan?
- 2Fluorescence microscopy at highest spatial and temporal resolution
- 3The Mechanics of the Immune System
- 4Resolve Biosciences Launches New Era in Single-Cell Spatial Analysis
- 5Quick look under the skin
- 6New ion trap to create the world's most accurate mass spectrometer
- 7How does your computer smell?
- 8Clocking electron movements inside an atom
- 9Sartorius closes 2020 with strong growth
- 10A clear path to better insights into biomolecules
- Researchers develop blood test for depression, bipolar disorder
- Doping by athletes could become tougher to hide with new detection method
- Tiny brains grown in 3D-printed bioreactor
- LabVantage Solutions Names Digital Transformation Veteran Mikael Hagstroem as Chief Executive Officer
- PerkinElmer Completes Acquisition of Oxford Immunotec