DNA array

the small Bond number value indicates strong effect of surface tractive force relative to the force of gravity. 

The surface tension gradients can be important in very thin liquid layers or in reduced gravity environment (microgravity). For example, a crystal grown from its melt under reduced gravity is governed by convection driven by thermally induced surface tension gradients rather than buoyancy forces. 

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The development of DNA sensors and high-density DNA arrays has been prompted by the tremendous demands for innovative analytical tools capable of delivering the genetic information in a faster, simpler, and cheaper manner at the sample source, compared to traditional nucleic acid assays. Nanoparticle-biopolymer conjugates offer great potential for DNA diagnostics and can have a profound impact upon bioanalytical chemistry. Nanoparticle/polynucleotide assemblies for advanced electrical detection of DNA sequences have been reviewed by Wang [145]. 

Chemiker sind der Zelle auf der Spur, Handelsblatt, August 2000 Plant cells as model for micro-reactor development availability of micro-flow devices German leadership first production applications BASF s motivation spotting for DNA arrays materials for micro reactors Merck production plant smallness for efficiency, but not an end in itself [232],... 

Two features of expression profiling make it the most productive approach to study biological systems for the immediate future. First, the present efficiency with which investigators can obtain global and quantitative information with DNA arrays exceeds that of proteomic techniques. Second, RNA expression profiles provide an extremely precise and reproducible signature of the state of the cell that probably reflects albeit indirectly, the functional state of all proteins (Young, 2000, p. 13)-... 

Young, R. A. (2000), Biomedical discovery with DNA arrays , Cell, 102, 9-15. 

Schlotterer, C. and Tautz, D. (1994) Chromosomal homogeneity of Drosophila ribosomal DNA arrays suggests intrachromosomal exchanges drive concerted evolution. Current Biology 4, 777-783. 

Rockett JC et al. Application of DNA arrays to toxicology. Environ Health Persp 1999 107 681-685. 

Taton, T.A., Mirkin, C.A. and Letsinger, R.L. (2000) Scanometric DNA array detection with nanoparticle probes. Science, 289, 1757-1760. 

DNA array-CGFI data were provided by Sandy DeVries at Dr. Fredric Waldman s Lab at UCSF. RNA extraction experiments were technically performed by Cheng Liu and Kelly Smith. Both studies were supported by NUT grant 1 R33 CA103455. Use of human tissues has been exempted under 45 CFR 46.101 (b) and was approved by the Institutional Review Board (IRB 009071) at USC. 

DNA arrays certainly offer an extremely high degree of multiplex capability for testing for multiple targets simultaneously in confirmatory assays. As the methods for detecting hybrids on the arrays improve, perhaps it will be possible to eliminate the requirement for PCR. PCR does amplify targets of interest to levels where detection is currently possible, but the... 

Though protein arrays borrow extensively from DNA-arrays, there are fundamental differences ... 

Brockman JM, Fmtos AG, Com RM (1999) A multistep chemical modification procedure to create DNA arrays on gold surfaces for the study of protein-DNA interactions with surface plasmon resonance imaging. J Am Chem Soc 121 8044-8051... 

Shumaker-Parry JS, Aebersold R, Campbell CT (2004) Parallel, quantitative measurement of protein binding to a 120-element double-stranded DNA array in real time using surface plasmon resonance microscopy. Anal Chem 76 2071-2082... 

Although the manufacture and use of DNA arrays have been commercialized with automatic operation, there are some important challenges for researchers and developers of the biochips. 

Without highly specific binding to proteins on the chip, thorough washing of the array may remove specific binders as well as non-specific binders. Protein bindings cannot offer a universal detection scheme like hybridization used in DNA arrays, which makes it difficult to discover enough probes for proteomics. 

DNA arrays are also useful in the studies of transcriptional dysregulation for many diseases so as to discover how different genes express themselves under certain pathological and pharmacological conditions. 

In a DNA array, gene-specific probes are created and immobilized on a chip (silicon wafer, nylon or glass array substrate). Biological samples are labeled with fluorescent dyes or radioactivity. These labeled samples are then incubated with the probes to allow hybridizations to take place in a high fidelity manner. After incubation, non-hybridized samples are washed away and spot fluorescent or radioactivity signals resulting from hybridization can be detected. 

Many formats of DNA arrays are currently available in today s market. These formats include microarrays, oligonucleotide arrays, macroarrays, and microelectronic arrays. Choice of usage of any one of these formats would be very much dependent on the users research applications and budget. The different array formats can be differentiated by the... 

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