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Protein perspective
The FPALM microscopy system breaks a fundamental limit on the resolution lens-based microscopes, known as the diffraction barrier, which has exsisted for more than 100 years.
With the help of a newly invented microscope system, scientists at the University of Maine are taking a close look at a protein from influenza virus that allows infection to occur.
The microscopy system, called FPALM (Fluorescence Photoactivation Localization Microscopy), was invented to enable scientists to look at the molecular organization of cells by imaging samples labeled with a special kind of fluorescent marker. The FPALM microscopy system breaks a fundamental limit on the resolution of lens-based microscopes, known as the diffraction barrier, which has existed for more than 100 years.
Influenza uses the protein hemagglutinin (HA) to infect healthy cells. In the first step of infection, HA enables the virus to attach to the membrane of a healthy cell.
It is believed that the arrangement of individual HA molecules in the membranes is crucial for infection to occur. Until now, the limited resolution of conventional microscopes made it impossible to create images of such molecules on a small enough scale to test the biological models that predict how they may be organized.
The recent extension of FPALM to include 3-D imaging and provide information about the orientation of single molecules will help address important biological questions. Already, the ability to image living cells has helped UMaine scientists disprove several existing models of membrane organization.
The UMaine researchers, including Samuel Hess, a FPALM coinventor, along with colleagues at the Albert Einstein College of Medicine in New York and the National Institute of Child Health and Human Development in Maryland, published their findings on HA in the journal Nature Methods.
