Detection king system

Cross-/] structure has been demonstrated for Sup35pNM filaments. Serio et al. (2000) observed a 0.47-nm reflection by X-ray diffraction, and subsequently this reflection was shown to be meridional both by X-ray fiber diffraction (Kishimoto et al., 2004) and electron diffraction (King and Diaz-Avalos, 2004). In the Ure2p system, cross-/ structure has been established by electron diffraction from prion domain filaments preserved in vitreous ice (Fig. 7 Baxa et al, 2005). In addition, a 0.47-nm reflection was detected by both X-ray diffraction and electron diffraction from filament preparations of full-length Ure2p and the Ure2p1 65-GFP fusion, indicating that they contain the same structure (Fig. 7 Baxa et al, 2005). 

Detecting redundancy in a chemical communication system requires more rigorous testing of blends than is common in pheromone identifications. Typically, such identifications focus on the minimum number of compounds to duplicate the behavioral response stimulated by a female moth. A subtraction bioassay that documented no adverse effect of deletion of a compound could lead to the conclusion that the compound is not a pheromone component. Clearly redundant components could be overlooked in this way. Perhaps for this reason, very few cases of redundancy have been documented (but see Linn et al., 1984 Rhainds et al., 1994 King etal, 1995). 

J. Wan, K. King, H. Craven, C. Mcauley, S.E. Tan and M.J. Coventry, Probelia PCR system for rapid detection of Salmonella in milk powder and ricotta cheese, Lett. Appl. Microbiol., 30 (2000) 267-271. 

The response of this detector is based on the fact that the frequency output from piezoelectric material is influenced by the weight of the coatings or layers on its surface. This effect has been used for many years to measure trace concentrations of water vapor in a gas and xylene vapor in air has been detected by this means at concentrations as low as lO g/ml. It was first introduced as a GC detecting system by King [22]. The detector consists of a quartz crystal (coated with a high boiling liquid) that is appropriately situated in an electronic circuit that causes it to oscillate at its natural frequency. The oscillation frequency is continuously monitored by a separate circuit. 

Ayrton et al. have experimented with TFC with microbore (1 mm) and capillary (0.18 mm) formats for TFC. These columns reduce the excessive amount of mobile phase required for this technology and can provide greater sensitivity for sample-limited situations. At a flow rate of 130 /zL/min, these authors demonstrated the ability to achieve sub-ng/mL quantitation for an assay based on only 2.5 /zL of plasma [76]. More recently, this group performed TFC in a parallel four-column format. MS analysis was accomplished with a multiple sprayer-ESl interface and allowed for simultaneous LC-MS/MS detection [77]. In another example. King et al. used a commercial system based on four staggered TFC systems in conjunction with a modified autosampler to demonstrate increased throughput. These authors demonstrated the ability to pass a GLP-level validation with this system [78]. 

Importantly, King succeeded in the formation of a Fc-labeled 998-bp (base-pair) construct by PCR using T4 DNA polymerase in the presence of Fcl-dUTP. Incorporation of the redox label shows that Fcl-dUTP is suitable as a substrate for PCR. In contrast, Fc2-dUTP acts predominantly as a terminator in the PCR. The melting behavior of a 37-mer duplex containing five Fcl-dU residues reveals that the labeled nucleotide induces only a modest helix destabilisation, with T ,=71°C for a labeled duplex versus 75°C for the corresponding nonlabeled ds-DNA construct. King reports that the Fc-labeled DNA is detected at femtomolar levels by HPLC using a coulometric detector. Thus, it must be emphasized that the incorporation of the Fc label by PCR and its facile and cost-effective electrochemical detection should promote the use of this technique in nucleic acid analysis and may replace the more costly fluorescence-based detection systems. 

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