This is a patch of nanoscopic needles that was built to inject DNA and other nucleic acids directly into individual cells.
The technique, developed by scientists at Imperial College London and Houston Methodist Research Institute, constructs tiny porous groups of needles out of biodegradable silicon. Each needle is 1,000 times thinner than a human hair. The team showed that their innovation could be used to deliver therapeutic nucleic acids inside human and animal cells.
[The image (above) shows human cells (green) on the nanoneedles (orange). The nanoneedles have injected DNA into the cells’ nuclei (Blue). The image was taken by the researchers using optical microscopy. Image courtesy Chiappini et al./ICL.]
The trabecular meshwork of the eye acts as a filter located behind the cornea. Behind the cornea is fluid to protect the eye from dust, wind, and other disturbances. We need this fluid for proper eye function, and it needs to be properly drained to prevent unwanted build-up. The trabecular meshwork makes this possible. When it cannot function properly, a disease called glaucoma results. The vision loss associated with glaucoma occurs when the fluid pressure in the cornea causes damage to the optic nerve, the nerve responsible for sending “sight” messages to the brain.
Image by Carmen Laethem, Aerie Pharmaceuticals, USA.
Polarized light microscopy is an optical microscopy technique involving the use of light polarization. Simple techniques include illumination of the sample with polarized light. More complex microscopy techniques include differential interference contrast microscopy and interference reflection microscopy.
These illumination techniques are most commonly used on birefringent samples where the polarized light interacts strongly with the sample and so generating contrast with the background. Polarized light microscopy is used extensively in optical mineralogy.
This optical microscopy technique is capable of providing information on absorption color and optical path boundaries between minerals of differing refractive indices, in a manner similar to brightfield illumination, but the technique can also distinguish between isotropic and anisotropic substances.
Furthermore, the contrast-enhancing technique exploits the optical properties specific to anisotropy and reveals detailed information concerning the structure and composition of materials that are invaluable for identification and diagnostic purposes.
Breaking The Supposed Limit In Seeing The Microscopic World Earns Three Chemistry Nobel
by Michael Keller
Three researchers were awarded the 2014 Nobel Prize in Chemistry today for breaking through what was thought to be an absolute optical limit in seeing microscopic objects like viruses and molecules.
The Nobel committee responsible for deciding the winners chose to honor the separate work of two Americans, Eric Betzig and William Moerner, and German Stefan Hell. These scientists pioneered what is called super-resolved fluorescence microscopy, which has opened up a whole new frontier for understanding how life works at the nanoscale. (Txchnologist has previously featured more of Betzig’s groundbreaking work here.)
“I was sitting in my office when the call from Stockholm reached me,” said Hell, who is the director of the Max Planck Institute for Biophysical Chemistry. “I am enormously gratified that my work and that of my colleagues has received the highest distinction for scientific research."
Their innovations, using light to excite molecules that have been tagged with fluorescent markers, are now being used around the world. They are letting researchers use visible light to glimpse separate objects that are closer together than what was thought to be the limit of 0.2 microns. This minimum is called the Abbe diffraction limit, which is half the length of the wavelength of the light used to see something through a microscope.