Slab gel electrophoresis with

An important development in CE technology that has helped to promote the analysis of PCR products by CGE is the introduction of laser-induced fluorescence (LIF) detection [4-7]. Because LIF can increase the sensitivity of detection for dsDNA by more than 400-fold over UV detection, it has become the method of choice for the vast majority of dsDNA separations [5]. A practical illustration of the advantage of LIF detection is that typical separations of PCR products by slab-gel electrophoresis with ethidium bromide staining require approximately 5 ng of DNA per band for adequate detection, whereas, with CGE-LIF, sub-picogram levels of DNA are readily detected [6]. 

Zheng J, Odake T, Kitamori T, Sawada T. Miniaturized ultrathin slab gel electrophoresis with thermal lens microscope detection and its application to fast genetic diagnosis. Anal Chem 1999 71 5003-8. 

The STR data generated at NIST were based on amplifying i.o ng of the genomic DNA with fluorescent labelled primers. The PCR amplified products were analyzed by slab gel electrophoresis followed by imaging with a Molecular Dynamics Fluorl-mager 595 or by capUlary electrophoresis using a PE-ABI 310 Genetic Analyzer. 

The extraordinary complexity of human genes and their products has encouraged the development of extremely high-resolution analytical methods.75 Capillary electrophoresis is competitive with slab gel methods, with resolution up to the order of about 1,000 base pairs for sequencing, sizing, and detection of mutation. Reversed phase HPLC is useful for restriction digest mapping and MALDI-MS up to about 1000 base pairs. 

Originally, polyacrylamide was used as an anticonvective additive in slab gel electrophoresis,79 but later its molecular sieving capability was also utilized.80 Polyacrylamide is a polymer built exclusively from monomeric units, with or without cross linking.81 A chemically cross-linked network is... 

A schematic representation of a CE system is presented in Figure 9.1. In this diagram, the CE components have obvious counterparts to those found in slab gel electrophoresis. Instead of buffer tanks there are two small buffer reservoirs, and the capillary takes the place of the gel (or more accurately, a gel lane). The capillary is immersed in the electrolyte-filled reservoirs, which also make contact with the electrodes connected to a high-voltage power supply. A new feature to the conventional gel electrophoresis format is the presence of an online detection system. 

Thereafter, approximate quantitative determinations of the carbohydrate content of the microbubble glycopeptide surfactant were made through the use of degradative enzymes. Table 4.3 summarizes the results from polyacrylamide (slab) gel electrophoresis of glycopeptide surfactant treated with P-N-acetyl-hexosaminidase, both alone and with endoglycosidase H. The... 

Capillary gel electrophoresis (CGE) with polymer solutions is about 8 to 10 times faster than slab gel electrophoresis. However, the single-lane nature of CE was unable to compete in throughput with slab gel instruments, which are run in parallel. This led to the development of capillary array electrophoresis (CAE) [38] in 1992. As the name suggests, electrophoresis is performed in an array of capillaries to run multiple samples in parallel. Figure 8.20 shows a microfabricated capillary array system [39] on a glass wafer consisting of 96 channels. 

Capillary electrophoresis combines the separation principles of gel electrophoresis with the throughput and detection methods of HPLC. It overcomes the disadvantages of slab gel electrophoresis, including slow and labor intensive procedures and the difficulty and inaccuracies of quantitation. CE is... 

The separation principle in capillary gel electrophoresis (CGE) is the same as that of slab gel electrophoresis. Most often CGE is used in a denaturing mode with the incorporation of SDS and is referred to as SDS-CGE. As such, separation is based on the protein s molecular mass and, due to the sieving mechanism of the gel, smaller proteins migrate past the detector first. The use of a gel material and SDS decreases the EOF and eliminates protein adsorption to the capillary walls further ensuring that migration is based on molecular mass. This precludes the need for additives and coated capillaries. 

Capillary SDS-gel electrophoresis is a rapid automated separation and characterization technique for protein molecules and is contemplated as a modern instrumental approach to sodium dodecylsulfate-polyacrylamide slab-gel electrophoresis (SDS-PAGE). Size separation of SDS-protein complexes can be readily attained in coated capillaries filled with cross-linked gels or non-cross-linked polymer networks. Figure 9 depicts one of the early applications of the technique for the analysis of a standard protein test mixture ranging in size from 14.2 to 205 kDa. 

Initially, gels were prepared within the capillary by copolymerization of acrylamide with bisacrylamide [9] as in slab gel electrophoresis. The capillary wall was coated with an acrylate as described above to remove the EOE Thus the gel could also be chemically fixed on the wall. Agarose which can be thermally mobilized has also been used [10]. With these gels the problem discussed above arose. Therefore liquid gels were introduced [11] after they had already been proposed for classical electrophoresis [12]. Some remarks on the properties of the sieving media will be given as the information found in the literature can be very confusing. 

Forensic science ink analysis is one of the most traditional analytical fields. Currently, thin-layer and column chromatography as well as slab gel electrophoresis are used to investigate ink composition, but, recently, CZE has been tentatively applied, with encouraging results (Fanali and Schudel, 1991). 

---