UV crosslinks

Fig. 31 Interaction of a peptide-diacetylene (as structure 2 above, but with the NHCOCH3 replaced by NHCOCH2CH2COOCH3) with an AFM tip. Left. The AFM tip has broken a fibril that had no UV crosslinked diacetylenes while trying to move it. Middle and right UV crosslinking allows manipulation with the AFM tip without damaging the fibril. Adapted with permission from Jahnke et al. [71]. Copyright Wiley-VCH...

By using an in vitro UV-crosslinking approach, bacteria-purified recombinant CPEB3 has been demonstrated to interact with the 2> UTR of GluR2 mRNA. To test whether this interaction occurs in vivo, hippocampal neuron cultures are ultraviolet (UV)-irradiated, homogenized, and immunoprecipitated with CPEB3 IgG or nonspecific IgG (Huang et al, 2006). Three plates of 2- to 3-week-old cultured neurons ( 6—8 million... 

After 2 h incubation of the prepared antibody beads with UV-crosslinked extract in a cold room, the beads are washed 4 x with 100 /A RIPA buffer (50 mMTris-HCl pH 7.5, 150 rnMNaCl, 1% NP-40, 0.5% sodium deoxycholate, and 0.1% SDS) and lx with genomic DNA lysis buffer (50 mM Tris, pH 7.4, 10 mM EDTA, 500 mM NaCl, 2.5 mM DTT, 0.5 mM spermidine, 1% Triton X-100). Approximately 300 /(I of PK solution (1 mg/ml proteinase K in genomic DNA lysis buffer and 0.2 U//A RNase inhibitor) is added to the total lysate previously kept on ice and the beads are then incubated at 37° for 30 min. Gently flick the tubes to resuspend the beads every 10 min during the incubation. After removal of the proteinase K solution, 300 /A of RNA extraction solution (4 M guanidine thiocyanate, 0.5% sarkosyl, and 25 mM sodium citrate, pH7) is added to the beads, incubated for 10 min and the supernatant is mixed with 30 fig yeast tRNA (as a carrier) and 30 fil of 3 M sodium acetate. The RNA solution is phenol-chloroform extracted, ethanol-precipitated, and the pellet washed once with 70% ethanol. The dry pellet is used for 1st strand cDNA synthesis, followed by PCR analysis. The removal of proteins... 

The chip with dried spots was covered with a UV transmission filter, and then placed into UV crosslinking instrument. 

To demonstrate the UV crosslinkability of the polymers formed having pendant acyloxyimino groups, copolymers of bisphenol diacrylate and 1,6 hexanediol diacrylate were prepared by thermal methods with 5% (by weight) of pyrene oxime acrylate and phenanthrene oxime acrylate, both of which have considerable absorption in the region of 320-360 nm. The polymerization was stopped before the gel point and the prepolymer solutions were then irradiated with light from a monochromator at the maximum of... 

TABLE 7 UV Crosslinking of Copolymers with Pendant Groups... 

In summary, fillers have a very limited effect on matrix crosslinking except when they are used as crosslinkers or when the effect is caused by the physical properties of the filler (e.g., Al(0H)3 in UV crosslinked systems). 

Nucleic acids are traditionally fixed to membranes in a vacuum oven (a conventional oven can be used for nylon membranes). The house vacuum system is usually adequate and baking of most membranes is at 80°C. UV crosslinking is an attractive alternative although it is only recommended for specific membranes. Special equipment is available for sophisticated, well-controlled UV irradiation (e.g., Stratalinker from Stratagene). However, conventional transilluminators available in the laboratory perform equally well. 

Baking of nitrocellulose or nylon is often optimum for 2 h in vacuo (vacuum not necessary for nylon). Shorter baking periods lead to inferior detectabilities for some brands or lots but not for others. On the other hand, it is necessary to bake for as short a time as possible since the nitrocellulose membranes become progressively more brittle. UV crosslinking in a Stratalinker is optimal at about 100-120 mJ/cm (at 254 nm) and takes less than a minute. UV... 

Diffusion coefficients for methanol (concentration range 1.0-5.0 M) in ion-exchange membranes of UV-crosslinked sulfonated poly(bis-3-methoxyphenoxyphosphazene) (134) have been reported to be much smaller than those in Nafion perfluorosulfonic ion-exchange membranes. Application of polyphosphazene-based membranes in methanol-based fuel cells has been reported. ... 

Insertion of a radioactive phosphate at a specific site for label-transfer by UV crosslinking.23... 

Inserting a photoreactive nucleotide for long wavelength UV crosslinking (see also Section 4.3.2).24... 

The bilayer devices were prepared using ethylene bis(4-azido-2,3,5,6-tetra-fluorobenzenesulfonamide) as a deep-UV crosslinker as described elsewhere [61]. The crosslinking occurs via a nonspecific nitrene insertion into alkyl C-H (and aromatic C-H) bonds and therefore does not affect the primary conjugation. 

Fig. 9.10 Study of UV-curable polynorbonenes (a) Chemical structures of the precursor polymers (b) efFect of UV-crosslinking of the polynorbonene-based HTL on the external quantum efficiency of OLEDs of the structure ITO/HTL/AlQ3/Mg.

Preparation and Characterization of UV-Crosslinkable Pressure-Sensitive Adhesives... 

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