June 21, 2017 These fluorescence images show a matrix representing 124 distinct metafluorophores, that are generated by combining three fluorescent dyes with varying intensity levels. In the future, the metafluorophore's unique and identifiable color patterns can be used to analyze the molecular components of complex samples. Credit: Wyss Institute at Harvard University
Biomedical researchers are understanding the functions of molecules within the body's cells in ever greater detail by increasing the resolution of their microscopes. However, what's lagging behind is their ability to simultaneously visualize the many different molecules that mediate complex molecular processes in a single snap-shot.
Now, a team from Harvard's Wyss Institute for Biologically Inspired Engineering, the LMU Munich, and the Max Planck Institute of Biochemistry in Germany, has engineered highly versatile metafluorophores by integrating commonly used small fluorescent probes into self-folding DNA structures where their colors and brightness can be digitally programmed. This nanotechnological approach offers a palette of 124 virtual colors for microscopic imaging or other analytical methods that can be adapted in the future to visualize multiple molecular players at the same time with ultra-high definition. The method is reported in Science Advances.
With their new method, the researchers address the problem that thus far only a limited number of molecular species can be visualized simultaneously with fluorescence microscopy in a biological or clinical sample. By introducing fluorescent DNA nanostructures called metafluorophoresversatile fluorescent dyes whose colors are determined by how their individual components are arranged in 3-dimensional structuresthey overcome this bottleneck.
"We use DNA nanostructures as molecular pegboards: by functionalizing specific component strands at defined positions of the DNA nanostructure with one of three different fluorescent dyes, we achieve a broad spectrum of up to 124 fluorescent signals with unique color compositions and intensities," said Yin, who is a Core Faculty member at the Wyss Institute and Professor of Systems Biology at Harvard Medical School. "Our study provides a framework that allows researchers to construct a large collection of metafluorophores with digitally programmable optical properties that they can use to visualize multiple targets in the samples they are interested in."
The DNA nanostructure-based approach can be used like a barcoding system to visually profile the presence of many specific DNA or RNA sequences in samples in what is called multiplexing.
To enable the visualization of multiple molecular structures in tissue samples whose thickness can limit the movement of larger DNA nanostructures and make it difficult for them to find their targets, and to reduce the possibility that they attach themselves to non-specific targets producing false fluorescence signals, the team took additional engineering steps.
"We developed a triggered version of our metafluorophore that dynamically self-assembles from small component strands that take on their prescribed shape only when they bind their target," said Ralf Jungmann, Ph.D., who is faculty at the LMU Munich and the Max Planck Institute of Biochemistry and co-conducted the study together with Yin. "These in-situ assembled metafluorophores can not only be introduced into complex samples with similar combinatorial possibilities as the prefabricated ones to visualize DNA, but they could also be leveraged to label antibodies as widely used detection reagents for proteins and other biomolecules."
"This new type of programmable, microscopy-enhancing DNA nanotechnology reveals how work in the Wyss Institute's Molecular Robotics Initiative can invent new ways to solve long-standing problems in biology and medicine. These metafluorophores that can be programmed to self-assemble when they bind their target, and that have defined fluorescent barcode readouts, represent a new form of nanoscale devices that could help to reveal complex, multi-component, biological interactions that we know exist but have no way of studying today," said Wyss Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and the Vascular Biology Program at Boston Children's Hospital, and Professor of Bioengineering at the Harvard John A. Paulson School of Engineering and Applied Sciences.
Explore further: From super to ultra-resolution microscopy: New method pushes the frontier in imaging resolution
More information: "Sub100-nm metafluorophores with digitally tunable optical properties self-assembled from DNA" Science Advances (2017). advances.sciencemag.org/content/3/6/e1602128
Proteins mostly do not work in isolation but rather make up larger complexes like the molecular machines that enable cells to communicate with each other, move cargo around in their interiors or replicate their DNA. Our ability ...
Many biological and pathological processes are not strictly controlled by the presence, absence or function of biomolecules such as proteins or nucleic acids but rather by subtle changes in their numbers at specific locations ...
A new microscopy method could enable scientists to generate snapshots of dozens of different biomolecules at once in a single human cell, a team from the Wyss Institute of Biologically Inspired Engineering at Harvard University ...
A team at the Wyss Institute for Biologically Inspired Engineering at Harvard University has been awarded a special $3.5 million grant from the National Institutes of Health (NIH) to develop an inexpensive and easy-to-use ...
Much like the checkout clerk uses a machine that scans the barcodes on packages to identify what customers bought at the store, scientists use powerful microscopes and their own kinds of barcodes to help them identify various ...
Researchers at Columbia University have made a significant step toward breaking the so-called "color barrier" of light microscopy for biological systems, allowing for much more comprehensive, system-wide labeling and imaging ...
(Phys.org)A team of researchers at Universite Paris-Diderot has uncovered the reason for wobbling of wheeled suitcases. In their paper published in Proceedings of the Royal Society A, the group explains the physics behind ...
Biomedical researchers are understanding the functions of molecules within the body's cells in ever greater detail by increasing the resolution of their microscopes. However, what's lagging behind is their ability to simultaneously ...
There is a great deal of excitement around virtual reality (VR) headsets that display a computer-simulated world and augmented reality (AR) glasses that overlay computer-generated elements with the real world. Although AR ...
Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and Argonne National Laboratory have collaborated to design, build and test two devices that utilize different superconducting ...
Measurements at the Australian Centre for Neutron Scattering have helped clarify the arrangement of magnetic vortices, known as skyrmions, in manganese silicide (MnSi).
Hundreds of millions of pieces of space junk orbit the Earth daily, from chips of old rocket paint, to shards of solar panels, and entire dead satellites. This cloud of high-tech detritus whirls around the planet at about ...
Please sign in to add a comment. Registration is free, and takes less than a minute. Read more
More here:
Self-assembling reagents with tunable colors and brightness enable ... - Phys.Org