Startup to provide access to low-cost super-resolution microscopy

Oct. 15, 2015

A startup is working to introduce imaging reagents that provide super-resolution microscopy capabilities on standard microscopes.

DNA-PAINT and Exchange-PAINT technologies (right image) dramatically improve the limited resolution abilities of single-molecule microscopes (left image). Shown are structures of thin microtubule fibers (green) that build a skeleton within cells and mitochondria (magenta) as the cell's biochemical powerhouses both turned from blurry into super-sharp molecular images.

The Wyss Institute for Biologically Inspired Engineering at Harvard University (Cambridge, MA) launched Ultivue, a startup working to introduce imaging reagents that provide super-resolution microscopy capabilities on standard single-molecule microscopes. The launch falls on the heels of a worldwide licensing agreement between Harvard's Office of Technology Development (OTD) and Ultivue for the Wyss Institute's DNA-PAINT and Exchange-PAINT technologies, a highly versatile and inexpensive microscopy platform designed to visualize objects with molecular-scale resolution and unprecedented complexity.

DNA-PAINT and Exchange-PAINT technology distinguishes molecules at super-high resolution and allows researchers to visualize a large number of species at the same time using low-cost reagents, says Peng Yin, a Core Faculty member at the Wyss Institute and an Associate Professor of Systems Biology at Harvard Medical School. Yin led the DNA-PAINT and Exchange-PAINT effort at the Wyss Institute, and is the scientific founder of Ultivue. The technology, he says, allows them to study many processes at a molecular level, such as changes in chromosomes or minuscule neuronal structures. They could also use it to determine molecular states of diseases in a more comprehensive fashion and with much greater detail, providing an enabling platform for digital pathology.

Molecular objects that are closer together than 200 nm cannot be distinguished from each other in standard-resolution fluorescent microscopic images and instead appear as single blurry spots. Super-resolution microscopes have been developed to overcome this optical barrier, but their high cost can be prohibitive, and they often rely on specialized conditions and fluorescent dyes that can be turned on and off with the help of a laser. DNA-PAINT, on the other hand, can be performed on standard fluorescent microscopes using low-cost DNA-PAINT reagents, and yet surpass the resolving power of current super-resolution microscopes.

To accomplish this, DNA-PAINT leverages the physical properties of the genetic material, DNA. The key principle is based on the tunable association of two short complementary DNA strands—one is attached to the object to be visualized and the other to a fluorescent dye. By carefully designing the nucleotide sequence of the complementary DNA strands, the time the two DNA strands remain bound before being separated again can be precisely programmed. This transient DNA interaction typically results in 'blinking' of the fluorescent dye with targets being localized by the dye with much higher precision than would be possible by other means. By using different DNA sequences to label distinct targets, and applying the imager strands one target at a time, many distinct targets can be imaged sequentially using only one dye and one laser source. This so-called Exchange-PAINT variation lends itself to multiplexing that can visualize 10 and potentially up to 100 different molecular species.

Supported by an NIH Transformative Research Award, an NIH Director's New Innovator Award, an NIH BRAIN Initiative Award, an NSF Expedition in Computing Award, an NSF Faculty CAREER Award, grants from ONR, and the Wyss Institute's translational funding, Yin and colleagues increased the resolution of the initial DNA-PAINT technology and added key capabilities to their platform, including multiplexing and compatibility with antibodies, which are broadly used target-specific reagents. The team also engaged with academic partners to successfully test and de-risk a beta version of the future reagent kit on various biological samples.

Ultivue will use super-resolution DNA-PAINT and Exchange-PAINT as its defining technologies to develop and expand a portfolio of multiplexed super-resolution-enabling and enhancing products. Beside Yin, Ultivue's co-founders also include Ralf Jungmann, a former postdoctoral fellow in Yin's Wyss Institute lab, who co-developed the technologies and now is a Group Leader at the Max Planck Institute of Biochemistry and the Ludwig Maximilian University in Munich, Germany. Additionally, Yin's former postdoctoral fellows at the Wyss Institute, Xi Chen and Mael Manesse, will be joining the company as Staff Scientists, contributing further expertise to Ultivue's product development efforts.

Full details of the DNA-PAINT and Exchange-PAINT technologies appear in Biophysical Journal; for more information, please visit http://dx.doi.org/10.1016/j.bpj.2014.11.2608.