Greiner Bio-One's recent release of streptavidin-coated microplates is the latest example of an expanding marketplace for researchers who print their own protein microarrays.
However, while this and similar developments support the belief that interest in homebrew protein arrays has been mounting over the past year, they haven't caught everybody's attention.
"The market is growing as people become aware of the advantages that [this technology] presents," Jan Seldin, Greiner Bio-One's US product manager, told ProteoMonitor's sister publication BioArray News earlier this month.
Seldin's company has been selling streptavidin-coated slides for three years, and decided to invest more in the US market for streptavidin-coated products with the introduction of the new microplates. The company claims that the plates, available in 96- and 384-well formats, are useful for arraying proteins and antigen-antibodies.
"The plates are used for a combination of ELISA and spot arraying," explained Seldin. "They are used in drug discovery to make assays more sensitive."
"Since protein microarraying is still in an early stage," and the protein world is significantly more diverse and complex than the DNA world, "we also expect a strong ongoing need for further optimized application-specific protein microarray surface chemistries and products."
According to Seldin, as well as others who sell streptavidin-coated products, streptavidin is an ideal coating because it bonds strongly to biotin, the reagent that is used in binding proteins, DNA, and other molecules to the array.
"We believe that the future protein array market demands several specialized coating chemistries due to the diverse nature of the different protein probes," Markus Boehm, international product manager for microarray solutions at Schott-Nexterion, said in a June interview (see BAN 6/15/2005).
Schott Nexterion recently signed an agreement with Denver-based Accelr8 to begin producing and selling hydrogel streptavidin-coated slides, which use Accelr8's proprietery OptiChem technology.
Last week, Lutz Wehmeier, Schott's general manager for microarray solutions, said that the HS slides would be available in September.
Lutz said that because the protein array market is still young, the company's products for homebrew arrays are likely to diversify in coming years.
"Since protein microarraying is still in an early stage," and the protein world is significantly more diverse and complex than the DNA world, Wehmeier said, "we also expect a strong ongoing need for further optimized application-specific protein microarray surface chemistries and products."
One of the products in the pipeline for Schott is an upgrade to its MPX slides, which were released a year ago and allow users to run experiments on slides with all of Schott's coating chemistries. Experiments can be multiplexed using Schott's MPX 16, which has a 16-well format, and the MPX 48, which allows 48 separate microarray experiments to be run in parallel.
In direct competition with Greiner's new offering, Wehmeier said that Schott is "now in the process of launching a microtiter plate product line."
"Together with a significant industrial partner, we have developed an optimized chemistry and kit design," Wehmeier said. He said that the microtiter plate product line will "be available for all [Schott's] standard coating chemistries as well as the HS streptavidin chemistry" and "will initially have 96 distinct reaction areas."
Wehmeier said that Schott plans to introduce a 384-well microtiter plate following the release of the other MTP products in the future as well.
While Schott-Nexterion and Greiner Bio-One's actions clearly show that interest in homebrew protein arrays has been mounting over the past year, the flurry of new activity hasn't caught everybody's attention.
For example, Corning's life science's division, which sells chemistry-coated glass substrates and considers itself the market leader (see BAN 5/11/2005), has yet to toss its hat in the streptavidin-slide arena.
Anis Khimani, Corning's microarray business manager, told BioArray News earlier this month that while the company has the ability to release streptavidin-coated products, it had no plans to do so.
"We have the technology, of course, we have different formats of microplates," Khimani said. "[A]t this time we don't have one, but there is always a continued effort to develop substrates."
Rather than focus on streptavidin and other chemistry-coated substrates as rivals Greiner and Schott are doing, Corning has other products in the pipeline. Robb DeCosta, the former microarray manager at Corning, told BioArray News in May that the company had just released an epoxide-coated substrate, and that an upgraded version of the Pronto! Plus microarray kit Corning developed with Promega would be launched later this year. The kits come with tools for RNA isolation, labeling, and hybridization.
Khimani added that the Pronto! Plus kit "covers 60 to 70 percent [of the market] for reagents in the microarray area." He estimated the total reagent market to be "just over $100 million right now."
Schott Nexterion is also planning on introducing a similar "total solution" kit based on an agreement with Operon Technologies that includes slides, reagents, dyes, and 70-mer oligos. Schott's Boehm said that that kit should hit the marketplace shortly after Corning's enhanced Pronto! Plus kit does, at the end of September.
This article originally ran in ProteoMonitor's sister publication BioArray News.
— Justin Petrone ([email protected])