Faster and more specific staining using HIVSNAP could surmount those shortcomings and thereby complement biochemical analyses of Gag distribution. In addition, the possibility to chose between differently colored dyes renders HIVSNAP a versatile tool for multi-color applications, e.g. for investigation of dynamic interactions between HIV Gag and individual host cell factors. Furthermore, the SNAP-tagged viral protein can be labeled with synthetic dyes whose photochemical properties are tailored to the requirements of super-resolution microscopy techniques. In summary, the virus derivative described here opens a variety of possibilities which will allow more detailed investigation of HIV-cell interaction by modern microscopic techniques. Entry efficiency was determined by a standard HIV fusion assay . Briefly, viral particles were prepared from 293T cells cotransfected with the indicated HIV proviral derivative and pMM310 . Particle concentration was determined by quantitative immunoblot using antiserum raised against HIV-1 CA. Serial dilutions of virus were used to infect JC53 cells seeded in 96-wells one day prior to infection. Following incubation at 37uC for 6 h, cells were washed with CO2-independent DMEM and incubated for 12 h at room temperature using BEZ235 CCF2-AM according to the manufacturer��s protocol. Cells were fixed with 3% PFA/PBS and NSC 136476 Hedgehog inhibitor fluorescence intensities at Em 447 nm and 520 nm were determined in a multiwell fluorimeter . The ratio of fluorescence emission at 520 nm over emission at 447 nm was calculated and normalized to the corresponding ratio obtained for uninfected cells to yield relative entry efficiencies. Amyloid diseases are related to anomalies in the folding process of certain proteins that may form insoluble fibril deposits. They include over 20 clinically relevant disorders, among which neurodegenerative disorders such as Alzheimer��s disease, and non neuropathic conditions such as type-II diabetes . Amyloid fibrils share common structural features despite the considerable diversity in the primary sequence of the constituent proteins. They are rich in b-sheet structures and the ordered regions adopt the classic cross-b structure in which individual strands in the b-sheets run perpendicular to the long axis of the fibril with the inter bsheet hydrogen bonds oriented parallel to the fibril axis .