New chemical tools to modify and study biomolecules

Understanding the structure and metabolism of cells and living organisms is essential for the development of new drugs and diagnostics. The availability of chemical tools that allow scientists to edit biomolecules, like proteins, ...

Breathing new life into dye-sensitized solar cells

Researchers at the Institute for Integrated Cell-Material Sciences at Kyoto University have made a popular type of dye-sensitized solar cell more efficient by adjusting and updating its structure. Published in the Journal ...

Painless skin patch collects fluid for diagnostic testing

Although blood contains a wealth of potential biomarkers of disease, it can be challenging to obtain and analyze. There's the anxiety patients experience when a large needle has to be stuck into a vein, and for many tests, ...

Self-healing DNA nanostructures

DNA assembled into nanostructures such as tubes and origami-inspired shapes could someday find applications ranging from DNA computers to nanomedicine. However, these intriguing structures don't persist long in biological ...

Location is everything for plant cell differentiation

While the fate of most human cells is determined by their lineage—for example, renal stem cells go on to form the kidney while cardiac progenitor cells form the heart—plant cells are a little more flexible. Research shows ...

Wristbands do a health check while you work out

Next-generation fitness sensors could give deeper insights into human health through noninvasive testing of bodily fluids. A stretchy patch developed at KAUST could help this approach by making it easier to analyze sweat ...

Tiny light-up barcodes identify molecules by their twinkling

An imaging technique developed at Duke University could make it possible to peer inside cells and watch dozens of different molecules in action at once—by labeling them with short strands of light-up DNA that blink on and ...

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Dye

A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber.

Both dyes and pigments appear to be colored because they absorb some wavelengths of light more than others. In contrast with a dye, a pigment generally is insoluble, and has no affinity for the substrate. Some dyes can be precipitated with an inert salt to produce a lake pigment, and based on the salt used they could be aluminum lake, calcium lake or barium lake pigments.

Dyed flax fibers have been found in the Republic of Georgia dated back in a prehistoric cave to 36,000 BP. Archaeological evidence shows that, particularly in India and Phoenicia, dyeing has been widely carried out for over 5000 years. The dyes were obtained from animal, vegetable or mineral origin, with no or very little processing. By far the greatest source of dyes has been from the plant kingdom, notably roots, berries, bark, leaves and wood, but only a few have ever been used on a commercial scale.

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