Microarray chips microarrays

DNA microarrays, or DNA chips consist of thousands of individual DNA sequences arrayed at a high density on a single matrix, usually glass slides or quartz wafers, but sometimes on nylon substrates. Probes with known identity are used to determine complementary binding, thus allowing the analysis of gene expression, DNA sequence variation or protein levels in a highly parallel format. 

The second part of this paper considers genetic chips or microarrays as one recent tool developed to deal with the reappreciated complexity of... 

An animation of how to run a simple experiment using a microarray (this is like the DeRisi exper-iment) by A. Malcolm Campbell of Davidson college is available at http //www.bio.davidson.edu/ courses/genomics/chip/chip.html (accessed 13-04-01). 

In contrast to high density arrays low density arrays are made by deposition of pre-synthesized oligonucleotides or proteins on activated surfaces. There are several printing techniques for fabricating microarrays Non-contact biochip arrayers, commonly based on the piezoelectric effect, can apply controlled sub-nanoliter probe volumes to pre-specified locations on the chip surface. Due to the fact that the dispenser does not touch the surface, a non-contact arrayer provides low risk of contamination and is most suitable for printing on soft materials such as hydrogels. 

A scanner with two lasers for Cy3 and Cy5 labeling is fairly good enough for most of the microarray experiments. However, multiple lasers are necessary for simultaneous detection of all four nucleotide polymorphisms in chip-based SNPs detection. Besides, an extra third flurophore attached to a sequence that specifically binds to a linker region of the DNA spots could be used for spotting quality control. 

Currently, protein microarrays can be divided into various types depending on the strategies to be chosen. For example, according to the array structure and shape, protein microarrays include 3D-surface structure [30, 31], nanowell [32], and plain chips [33-36], Meanwhile, considering the field of application, protein microarrays can be classified into five categories antibody array, antigen or reserve array, functional array, capture array, and solute array. Table 11.6 shows the differences among them. 

The use of biochips in basic biological research has provided information that was heretofore inaccessible. Protein chips, especially functional microarrays, are used to... 

Protein microchips have a significant impact on the development of safer drugs through the comprehensive profiling of drugs or lead compounds for effects. Zhu et al. [35] used a microarray of an entire eukaryotic proteome to screen different biochemical activities. First, protein chips can screen potential lead compounds at high throughput... 

Fig. 3.27 KAMINA gas sensor chip with gradient microarray mounted in its housing.

However, in addition to its low production costs and excellent gas analytical features, the gradient microarray chip offers further advantages over the classical arrays consisting of separate gas sensors of different chemistry. Since all sensor ele-... 

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