‘Virtual’ mouse brains now available online

A multi-institutional consortium including Duke University has created startlingly crisp 3-D microscopic views of tiny mouse brains — unveiled layer by layer — by extending the capabilities of conventional magnetic resonance imaging.

“These images can be more than 100,000 times higher resolution than a clinical MRI scan,” said G. Allan Johnson, Duke’s Charles E. Putman Distinguished Professor of radiology and professor of biomedical engineering and physics. He is first author of a report describing the innovations set for publication in the research journal NeuroImage. View it online 

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Tiny particles pave way for new bedside diagnostics

MIT researchers have created an inexpensive method to screen for millions of different biomolecules (DNA, proteins, etc.) in a single sample-a technology that could make possible the development of low-cost clinical bedside diagnostics.

The work, based on tiny customizable particles, could also be used for disease monitoring, drug discovery or genetic profiling. Even though the particles are thinner than the width of a human hair, each is equipped with a barcoded ID and one or more probe regions that turn fluorescent when they detect specific targets in a test sample.

Technique reveals inner lives of red blood cells

For the first time, researchers at MIT can see every vibration of a cell membrane, using a technique that could one day allow scientists to create three-dimensional images of the inner workings of living cells.

Studying cell membrane dynamics can help scientists gain insight into diseases such as sickle cell anemia, malaria and cancer. Using a technique known as quantitative phase imaging, researchers at MIT’s George R. Harrison Spectroscopy Laboratory can see cell membrane vibrations as tiny as a few tens of nanometers (billionths of a meter).

Immune cell communication key to hunting viruses

Immunologists at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have used nanotechnology to create a novel “biosensor” to solve in part a perplexing problem in immunology: how immune system cells called killer T-cells hunt down invading viruses.

They found that surprisingly little virus can turn on the killer T-cells, thanks to some complicated communication among so-called “antigen presenting” proteins that recognize and attach to the virus, in turn, making it visible to the immune system. T-cell receptors then “see” the virus, activating the T-cells.

Researchers watch brain in action

For the first time, scientists have been able to watch neurons within the brain of a living animal change in response to experience.

Thanks to a new imaging system, researchers at MIT’s Picower Institute for Learning and Memory have gotten an unprecedented look into how genes shape the brain in response to the environment. Their work is reported in the July 28 issue of Cell.

Nano Probe May Open New Window Into Cell Behavior

Georgia Tech researchers have created a nanoscale probe, the Scanning Mass Spectrometry (SMS) probe, that can capture both the biochemical makeup and topography of complex biological objects in their normal environment — opening the door for discovery of new biomarkers and improved gene studies, leading to better disease diagnosis and drug design on the cellular level. The research was presented in the July issue of IEE Electronics Letters.

Georgia Tech’s SMS Probe gently pulls biomolecules precisely at a specific point on the cell/tissue surface, ionizes these biomolecules and produces “dry” ions suitable for analysis and then transports those ions to the mass spectrometer.

Fluorescent Nanosensor Detects Cell Death

A team of investigators at Massachusetts General Hospital has developed a nanoparticle that signals when cells are undergoing apoptosis, the kind of cell death triggered by cancer therapies. The new nanoparticles could finally provide oncologists with a rapid assay that could tell them that a given therapy is working. This groundbreaking work was published in the journal Nano Letters.

Scientists Visualize Protein Interaction That May Initiate Viral Infection

Biologists at Purdue University have taken a “snapshot” of a Velcro-like protein on a cell’s surface just after it attached to the dengue virus, a linkup thought to initiate the early stages of infection.

The virus, which is spread by mosquitoes, infects more than 50 million people annually, killing about 24,000 each year, primarily in tropical regions.

Physicists create first robust DNA building blocks for use in nanofabrication

Physicists from the University of Oxford have designed the first structurally robust, self-assembling DNA building blocks. The DNA tetrahedra, 10,000,000,000 (ten thousand million) of which could fit on the head of a pin, could lead to the manufacture of complex nanostructures such as powerful electrical circuits.

Modified Atomic Force Microscopy Proves Critical to Uncovering Cell-growth Secret

Researchers using a customized atomic force microscope (AFM) have discovered new evidence for how the fibrous scaffolding within our cells, which is made of the protein actin, responds to obstacles in its environment.

The discovery demonstrates a technique for tracking a cell’s growth history, and if it proves valid outside of the laboratory, researchers may one day look for actin-growth clues while tracking the pathways of spreading cancers, immune cells, and other free-moving cells that crawl throughout the body.

Quantum Dots Nanosensor Detects DNA

Using tiny semiconductor crystals, biological probes and a laser, Johns Hopkins University engineers have developed a new method of finding specific sequences of DNA by making them light up beneath a microscope. The researchers, who say the technique will have important uses in medical research, demonstrated its potential in their lab by detecting a sample of DNA containing a mutation linked to ovarian cancer.

Scientists directly view immune cells interacting to avert autoimmunity

Using a new form of microscopy to penetrate living lymph nodes, UCSF scientists have for the first time viewed immune cells at work, helping clarify how T cells control autoimmunity.

The technique, known as two-photon laser-scanning microscopy, was able to focus deep within the lymph node of a diabetic mouse, allowing the researchers to show that immune cells known as T regulatory, or Treg, cells control the destructive action of rogue autoimmune cells when each of the two cell types interact with a third kind of cell.

New microscope allows scientists to track a functioning protein with atomic-level precision

A Stanford University research team has designed the first microscope sensitive enough to track the real-time motion of a single protein down to the level of its individual atoms. Writing in the Nov. 13 online issue of the journal Nature, the Stanford researchers explain how the new instrument allowed them to settle long-standing scientific debates about the way genes are copied from DNA–a biochemical process that’s essential to life.

In a second paper published in the Nov. 8 online issue of the journal Physical Review Letters, the scientists offer a detailed description of their novel device, an advanced version of the “optical trap,” which uses infrared light to trap and control the forces on a functional protein, allowing researchers to monitor the molecule’s every move in real time.

New microscope allows scientists to track a functioning protein with atomic

A Stanford University research team has designed the first microscope sensitive enough to track the real-time motion of a single protein down to the level of its individual atoms. Writing in the Nov. 13 online issue of the journal Nature, the Stanford researchers explain how the new instrument allowed them to settle long-standing scientific debates about the way genes are copied from DNA–a biochemical process that’s essential to life.

In a second paper published in the Nov. 8 online issue of the journal Physical Review Letters, the scientists offer a detailed description of their novel device, an advanced version of the “optical trap,” which uses infrared light to trap and control the forces on a functional protein, allowing researchers to monitor the molecule’s every move in real time.
“In the Nature experiment, we carried out the highest-resolution measurement ever made of an individual protein,” says Steven Block, professor of applied physics and of biological sciences. “We obtained measurements accurate to one angstrom, or one-tenth of a nanometer. That’s a distance equivalent to the diameter of a single hydrogen atom, and about 10 times finer than any previous such measurement.”