Even in the early stages of cancer, individual cancer cells can be found in the blood. Certain subsets of these circulating tumor cells can cause metastasis.
In cases of breast cancer, it is known that these cells can differ from the original tumor cells, which allows them to survive treatment to cause later recurrence. It could thus be quite informative to detect these cells in the blood and examine them more closely. In the journal Angewandte Chemie, researchers at the University of Washington (Seattle, USA) describe a new chip-based method that allows for the detection and isolation of tiny concentrations of such cells in blood.
The detection of circulating tumor cells is a difficult challenge because it requires the detection of quantities as low as one to ten cells per milliliter of blood—in the presence of large numbers of red blood cells and other cells. Conventional methods cannot manage this, but scientists led by Daniel T. Chiu have now developed a microfluidic system that allows for the analysis of 1 mL of blood within 20 minutes. The secret of their success is to virtually divide the sample into aliquots (portions) and to search these for the presence or absence of the desired cell types.
The blood is initially marked with fluorescent markers that specifically bind to the desired tumor cells. The sample is then passed through a system of microchannels, where it passes through a zone that is irradiated by a laser. The size of this zone determines the volume of the virtual aliquot; 2 nanoliters was found to work well. The laser causes the marker to fluoresce if marked cells are present. It can thus be determined whether or not an aliquot contains one (or more) of the desired cells. If the aliquot fluoresces, it is automatically pumped into a different channel than the fractions that do not fluoresce. The positive aliquots enter a filtration chamber. Red blood cells and the majority of blood cells pass through the filter; tumor cells are larger and are trapped. They can be counted on the filter, examined by microscope, or removed by micropipette for further examination.
By using a second marker, certain subpopulations, such as tumor stem cells, can be identified.
Experiments with blood containing a known number of breast cancer cells yielded a recovery rate of 93 % and a false positive rate of zero. Real blood samples from patients were also examined and the results compared with those from a clinically established system. The new microfluidic system proved to be significantly more sensitive. This new procedure has potential for monitoring treatment, aftercare, and the early detection of cancer.
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201108695
Daniel T. Chiu | Angewandte Chemie
A landscape of mammalian development
21.02.2019 | Max-Planck-Institut für molekulare Genetik
Atopic dermatitis: elevated salt concentrations in affected skin
21.02.2019 | Technische Universität München
Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.
The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...
For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.
The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...
Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens
Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...
Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light
When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...
The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized...
11.02.2019 | Event News
30.01.2019 | Event News
16.01.2019 | Event News
21.02.2019 | Life Sciences
21.02.2019 | Earth Sciences
21.02.2019 | Life Sciences