French fluorescence technology firm Cisbio is hoping to benefit from an exclusive agreement with nascent lanthanide tech shop Lumiphore that will enable it to upgrade its HTRF line of time-resolved fluorescence resonance energy transfer assays with Lumiphore’s proprietary Lumi4 technology.
Cisbio will incorporate Lumi4 into its entire product catalog by replacing its currently used fluorophore with Lumi4 to “the greatest extent possible,” according to Lumiphore’s chief operating officer, Willem Spiegel.
The Lumi4 technology is a lanthanide-based fluorescent molecule that was developed in Ken Raymond’s lab at the University of California, Berkeley.
Nathaniel Butlin, a senior scientist at Lumiphore, explained that all classes of fluorophores have two parts: the metal ion at the center and the chelating or sensitizing cage on the outside. This structure largely defines properties of the flurophore such as solubility, stability and brightness. Lumi4 technology uses a different cage and a different lanthanide relative to what Cisbio currently uses, he said.
Cisbio’s HTRF technology is based on a europium lanthanide. Lumiphore’s technology uses terbium instead, and offers a brighter signal and better stability than europium, Butlin said.
In follow-up e-mail to CBA News, Butlin said, “Lumi4 is a Tb-based fluorophore that is distinguished from other Tb-based molecules due to its unique sensitizing structure that combines high solubility and stability with exceptional brightness. Lumi4 is the first lanthanide bright enough to compete with conventional organic fluorophores in aqueous environments while still offering all the conventional benefits of lanthanide-based fluorophores.
”These benefits include millisecond lifetime leading to minimal background when used in time resolved mode, resistance to photobleaching allowing repeated cycling, large Stokes shift between excitation and emission wavelengths, and extremely sharp emission peaks,” he went on to say in the e-mail.
François Degorce, director of HTRF marketing and business development for Cisbio, told CBA News that the company was looking for a compound with increased stability, and found it in the Lumi4 technology.
In addition, the Lumi4 compound is very bright, Degorce said, which will enable new applications for Cisbio’s products in the field of biomolecular interactions, in particular for cell-based assays.
Lumi4’s stability and resistance to bleaching allows samples to be archived, which facilitates improved quality control comparisons between old and new data, said Degorce.
“When you run an assay in a homogeneous format and you run 100,000 compounds per day, for example, if for any reason the instrumentation has a problem, such as with the detection system at the end of the screen, you have two alternatives: either discard the plates completely and call it a loss, or keep the plates in a refrigerator or freezer to be read once the machine is working.”
“In the immediate future, we plan on incorporating this compound into our existing products, and then into entirely new ones,” said Degorce. “So this is a partnership that we see playing a role in our short-, mid-, and long-term plans.”
He declined to comment further on those plans, however.
According to Lumiphore’s Spiegel, Cisbio will launch products that have been upgraded with Lumi4 sometime in 2008. He said that Cisbio is currently doing its due diligence and going through its technical validation process.
“We really do not know how far this collaboration may go, and what its limits may be,” he said.
A Bright Future
Redwood City, Calif.-based Lumiphore was founded around five years ago by Kenneth Raymond of UCal-Berkeley and Stéphane Petoud of the University of Pennsylvania with funding from friends and family. Since then, the company raised an undisclosed amount of funding from German nanotechnology investment house Nanostart, Spiegel said.
According to the Nanostart web site, the company now owns more than 20 percent of Lumiphore.
“In the immediate future, we plan on incorporating this compound into our existing products and then into entirely new ones.”
The company has another alliance with Biostride, a manufacturer of antibodies, antigens, and enzyme conjugates of hormones and drugs of abuse. Spiegel said that Lumiphore has been working on a diagnostics project with Biostride in the field of toxicology for about two years.
He added that Lumiphore is also exploring opportunities in the field of DNA applications, but that is still in the very early stages.
“We are also working on second- and third-generation products and developing more advanced technologies as time goes by,” Spiegel said. He did not elaborate, however.
Butlin said that although some precedent exists for the use of lanthanide fluorescence in the diagnostic space, its use in DNA analysis is relatively new.
Spiegel described Lumiphore as a “virtual” company, with a staff of eight part-time consultants and no full-time employees. While the firm is considering hiring full-timers in the future, that decision has yet to be made.
One of the significant advantages of terbium is that its spectral properties make it an ideal donor for green fluorescent protein, said John Printen, business segment director for cell signaling at Invitrogen, in an e-mail to CBA News.
“The real advantage in having terbium- and europium-based reagents in your assay development ‘toolbox’ is the ability to multiplex readouts,” he said. For example, by choosing the appropriate lanthanide donor and a corresponding fluorophore, “the substrate protein concentration and the extent of phosphorylation of that substrate in a single microtiter plate well can be measured,” he said.
Printen said that the existing terbium-based assays on the market are “very sensitive,” and allow customers to easily miniaturize high-throughput screening assays to a 1,536-well format. However, he noted, “I think it remains to be seen whether the Lumiphore probes will offer substantial benefits to the end user.
“I, for one, will be very interested to see how Cisbio brings this technology to the marketplace, and will be following the impact it will have on how customers develop and execute HTS assays,” he said.