Probing biology's dark matter( A typical human mouth teems with as ma...)

A typical human mouth teems with as many as 700 different species of microbes. A handful of these have been specifically implicated in promoting gum disease, dental cavities, and bad breath, but for the most part, the make-up of this complex ecosystem and its impact on human health remain largely unexplored. A new device created by Howard Hughes Medical Institute (HHMI) researchers, however, may make some of the most reclusive members of this and other microscopic communities much more accessible for laboratory study.

The vast majority of microbes are notoriously resistant to growing in laboratory cultures because they are so intricately linked to their own unique ecosystems. Microbiologists have coaxed less than one percent of the bacterial species that inhabit natural environments into growing in culture. But a microfluidics device created by Howard Hughes Medical Institute investigator Stephen R. Quake and colleagues at Stanford University an intricate system of miniscule valves and chambers -- may help scientists who want to identify and characterize new microbes circumvent the need to culture them at all.

Research on the device published in the July 9, 2007, issue of the Proceedings of the National Academy of Sciences (PNAS) has far-reaching implications for the rapidly developing field of microbial ecology, as well as advancing microfluidics technologies, which could do for biology what silicon chips did for electronics. Quake and his colleagues have already used the device to analyze a rare bacteria found in the human mouth, using just a single cell.

Various methods have given scientists a glimpse of the profound diversity that characterizes different microbial worlds. One approach is to look for variations in the sequence of a specific gene found in all microorganisms; another is a complete inventory of all the pooled genes in a microbial community. These types of studies, however, yield few insights into the character of i
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Contact: Jennifer Michalowski
michalow@hhmi.org
301-215-8576
Howard Hughes Medical Institute
19-Jul-2007