Capillary Electrophoresis Equipment

Capillary electrophoresis equipment uses narrow-bore fused-silica capillaries to separate a complex array of large and small molecules. Capillary electrophoresis (CE) is used for the analysis of ions, and both basic and chiral pharmaceuticals. There are many types of capillary electrophoresis equipment, depending on the type of capillaries and the electrolytes used. Examples include capillary electrophoresis equipment for micellular electrokinetic chromatography (MEKC), capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), and capillary isoelectric focusing (CIEF).

Selecting capillary electrophoresis equipment requires a basic understanding of various CE techniques. Micellular electrokinetic chromatography (MEKC) is used for separating mixtures containing both ionic and neutral species. Capillary zone electrophoresis (CZE) is known as free solution CE and it provides constant field strength throughout the length of the capillary. Capillary gel electrophoresis (CGE) is used to separate the proteins and nucleic acids. Capillary isoelectric focusing (CIEF) separates amphoteric molecules such as proteins by electrophoresis in a pH gradient that is generated between cathode and the anode.

Capillary electrophoresis equipment differs in terms of operation. With micellular electrokinetic chromatography (MEKC), the surfactants are added to a buffer solution and the separation is done by differential partition between the solvent and micelle. Capillary zone electrophoresis (CZE) fills the capillary tube with aqueous buffer solution that contains both positive and negative ions. The surface of the capillary has a net negative charge because of Si-O chemical groups present in the glasslike material. Capillary gel electrophoresis (CGE) uses a gel which builds heat and is detrimental to separation. CGE is used for DNA sequencing and genotyping. Capillary isoelectric focusing (CIEF) combines with capillary reversed-phase liquid chromatography (CRPLC) using a micro injector as the interface for performing the 2-D protein separations from complex protein mixtures.

Capillary electrophoresis equipment is used in many different applications. Some examples include genetic analysis, the analysis of pharmaceuticals that contain nitrogenous bases, gunshot residue analysis, and counter-ion analysis in drug discovery. Genetic analysis equipment is used to determine a person’s ancestry, or to diagnose vulnerability to inherited disease. CE equipment for pharmaceutical analysis involves the separation of a compound and quantification of the compound. Capillary electrophoresis equipment for gunshot residue analysis and counter-ion analysis is also available.

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• The Third Way for ICH Q7A: A Proposal for Updating Guidance for API Inspections
  By Emil W. Ciurczak, Contributing Editor The time involved will diminish the profit margin and/or increase the cost of goods to the patients. Smaller, independent generic Pharma companies do not...
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  The analytical sleuthing to determine the nature and source of the heparin contaminant was impressive. Ram Sasisekharan, PhD, from MIT, at the behest of the FDA (in the person of Moheb Nasr),...
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