Researchers using microarray technologies for protein analysis came together for a two-day meeting in Berlin two weeks ago to discuss the latest developments in this growing field. The meeting, Protein Microarray Technology, included presentations on topics ranging from the construction of protein chips to assay development, examples of applications, and discussions of the microarray market. Following is a selection of some conference highlights:
Andrei Mirzabekov, director of the Engelhardt Institute of Molecular Biology in Moscow, gave the keynote lecture on microarrays of gel immobilized proteins or oligonucleotides. The gel environment, he noted, stabilizes proteins, increases the capacity of the chip and does not require protein modifications. Further, it enables reactions to be carried out in a homogeneous phase. Unlike other gel chips, these protein chips do not have any diffusion problems since the proteins are added before the gel is polymerized.
Mirzabekov is hoping to commercialize his gel chips soon in the form of a startup company called BioChip. These protein arrays, he believes, will comprise part of a widening spectrum of different types of microarrays: “There will be chips to study whole cells, whole tissues or even whole organisms, for example C. elegans,” he said.
Ruud de Wildt of Diversys in the UK discussed high density antibody arrays that were developed at the UK’s Medical Research Council (MRC). These arrays, which de Wildt and his colleagues first described in a Nature Biotechnology article published last year, involve high density gridding of bacteria containing antibody genes, followed by filter-based ELISA screening.
Since then, they have developed an improved version. “We developed a method for selecting and screening pairs of antigens and antibodies,” he said. The antigens are tagged in order to be identified immediately. At the moment, researchers can screen 30,000 clones for antibody-antigen pairs on the array using a mixture of three antigens, but de Wildt is expecting this number will rise.
“This will be useful for increasing the throughput when selecting antibodies,” said de Wildt, who is hoping to publish his results soon. The arrays are being commercialized by Diversys, a MRC spin-off biotech company, which de Wildt recently joined.
In addition to these protein chip reports, Nir Dotan of Glycominds in Israel presented his GlycoChip technology, a carbohydrate array with 50 different sugars ranging from one to five monosaccharides in length. This chip, which the company claimed is the first sugar microarray ever, serves to characterize carbohydrate-binding or ñprocessing proteins. It can also be used to assay for small molecules that inhibit protein-sugar interactions, and to characterize the immunogenicity of therapeutic proteins.
The chips will be commercially available next year in two formats. “We will be fully on the market in January 2002,” said Dotan. Glycominds will also offer its glycomics database containing information on carbohydrate-protein interactions.