Microchip technology

Tilib SV, Mirzabekov AD (2001) Advances in the analysis of DNA sequence variations using oligonucleotide microchip technology. Curr Opin Biotechnol 12 53-58... 

Among the various possibilities that offer the EC detection, ampe-rometry and conductimetry are, in this order, the most common. Although potentiometry results are a very interesting technique in many fields of Analytical Chemistry, it has not found enough echo in the microchip technology. Its incursion in microchips is related with the employment of ion-selective electrodes for Ba2+ determination [55] or potentiometric titration of iron ferrocyanide [56], but it has not yet been associated with CE microchips. 

Hybridisation can thus be used to produce probes, for example, for the detection of oligonucleotides in chick embryo tissue or of Epstein-Barr viruses (glandular fever) in transplant recipients - by detection of specific RNA strands. DNA dendrimers and corresponding detection devices have meanwhile become commercially available (Genisphere company). Fluorescence-labelled polynucleotide dendrimers have also been used for signal intensification in DNA microchip technology [59]. 

In spite of all these clear advantages, capillary isoelectric focusing is still not used as a routine method in bioanalysis, although more and more papers show important applications. Study of the proteome combined with microchip technology may, however, cause sudden progress in this innovative technique. In the past decade several reviews have appeared about CIEF separations [5-17]. This chapter summarizes the theory and the newest innovations, as well as applications of CIEF. 

One of the most important applications of capillary electrophoresis has been the separation of DNA for clinical purposes. Thus, it is logical that a major application of microchip technology is DNA separations. One of the first examples of a DNA separation on a microdevice with a clinical application was accomplished by Effenhauser et al. [61], This research demonstrated separation of fluorescently labeled oligonucleotides, ranging in size from 10 to 25 base pairs, in only 45 s in a 3.8-cm channel length. Because the DNA fragments were so... 

Principles and Applications in Analytical Chemistry and Microchip Technology... 

Given the important role of GE in protein separations (Ch. 17.3), an on-line combination of CE and MS would be a logical choice. CE-MS with ESI has been under development for many years [93-96]. CE is also an important technique in the development of microchip technology [86]. 

An application in microchip technology that highlights the limitation of the sole use of microtechnology is the use of a microfabricated filter to enhance the enrichment of fetal cells in a preparation that will be used for genomic studies. In this study, the goal was to provide a sample that contains 5 to 50 nucleated red blood cells (n-RBCs) of... 

AN INNOVATIVE SEPARATION PLATFORM ELECTROPHORETIC MICROCHIP TECHNOLOGY... 

Finally, it is anticipated that the trend toward miniaturizahon will conhnue and that applications that truly beneht from nanotechnology and microlluidics will become apparent over hme. While much attenhon has recently been given to Lab-on-a-Chip technology, MS has lagged behind other forms of detection. Current advances toward the interface between ESI and microchip technology suggest that MS applicahons will soon be more prevalent [133]. 

CHEMOMETRIC METHODS APPLIED TO GENETIC ANALYSES BY CAPILLARY ELECTROPHORESIS AND ELECTROPHORESIS MICROCHIP TECHNOLOGIES... 

Normally, the glass-based microchips have good performance because the surface property is similar to the inner surface of conventional capillaries and high optical transparency. The samples are normally loaded by EK injection and detected with UV or LIF detectors positioned at the end of the channel. In recent years, companies such as Agilent, Hitachi, and Shimadzu have developed equipment based on microchip technology for biochemical analysis, and such equipment is now commercially available (16). 

This chapter discussed several aspects of DNA analysis by CE and microchip technologies using polymer solutions as the sieving matrix. Analysis of DNA is a multivariate system by nature and both the separation and the result of the separation are suitable to a large number of chemometric tools. 

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