What is electroosmotic flow in capillary electrophoresis?
What is electroosmotic flow in capillary electrophoresis?
Electroosmotic flow is observed when an electric field is applied to a solution in a capillary that has fixed charges on its interior wall. Charge is accumulated on the inner surface of a capillary when a buffer solution is placed inside the capillary.
What is the mobile phase in capillary electrophoresis?
The heart of capillary electrophoresis (CE) is electroosmotic flow (EOF). This is the mobile phase “pump” in CE. Unlike gas chromatography (GC), there is no pressurized gas acting as the mobile phase in CE. Unlike high performance liquid chromatography (HPLC) these is no (high pressure) pumped mobile phase.
Can proteins exit capillaries?
Larger molecules can pass through the pores of fenestrated capillaries, and even large plasma proteins can pass through the great gaps in the sinusoids. Some large proteins in blood plasma can move into and out of the endothelial cells packaged within vesicles by endocytosis and exocytosis.
What does capillary electrophoresis detect?
Capillary electrophoresis (CE) is the primary methodology used for separating and detecting short tandem repeat (STR) alleles in forensic DNA laboratories worldwide. This chapter examines the general principles and components of injection, separation, and detection of STR alleles using CE.
What is electrokinetic injection capillary electrophoresis?
There are two commonly used injection methods for CE: hydrodynamic and electrokinetic. Hydrodynamic injection is accomplished by the application of a pressure difference between the two ends of a capillary. Electrokinetic injection is performed by simply turning on the voltage for a certain period of time.
Why does electroosmotic flow occur?
Electroosmotic flow occurs because the walls of the capillary tubing are electrically charged. The surface of a silica capillary contains large numbers of silanol groups (–SiOH). At pH levels greater than approximately 2 or 3, the silanol groups ionize to form negatively charged silanate ions (–SiO–).
What is capillary action of mobile phase?
Capillary electrochromatography (CEC) is a chromatographic technique in which the mobile phase is driven through the chromatographic bed by electroosmosis. Capillary electrochromatography is a combination of two analytical techniques, high-performance liquid chromatography and capillary electrophoresis.
What is zeta potential in capillary electrophoresis?
The zeta potential, ξ, also known as the electrokinetic potential is the electric potential at the interface of the double layer. Hence, in our case, it is the potential of the diffuse layer that is at a finite distance from the capillary wall.
How does a decrease in capillary oncotic pressure cause edema?
In conditions where plasma proteins are reduced, e.g. from being lost in the urine (proteinuria), there will be a reduction in oncotic pressure and an increase in filtration across the capillary, resulting in excess fluid buildup in the tissues (edema).
How do molecules pass through capillary walls?
Small molecules can cross into and out of capillaries via simple or facilitated diffusion. Some large molecules can cross in vesicles or through clefts, fenestrations, or gaps between cells in capillary walls. However, the bulk flow of capillary and tissue fluid occurs via filtration and reabsorption.
What is PCR capillary electrophoresis?
This alternative technique, hereafter called PCR-capillary electrophoresis (PCR-CE), applies capillary electrophoresis to determine the amplicons lengths, instead of DNA-sequencing as in NGS-DNA barcoding. We obtain a migration pattern that allows the detection of several peaks characteristic of multi-species samples.
What is capillary electrophoresis (CE)?
Capillary electrophoresis ( CE ), then is the separation of molecules using electricity and a very small tube called a capillary. How Does Capillary Electrophoresis Work? The capillary, which as we discussed is shaped like a tube, is open on each end, and each end is placed in a buffer.
What happens on the venule end of a capillary?
On the venule end of the capillary bed, blood pressure in the vessel is less than the osmotic pressure of the blood in the vessel. The net result is that fluid, carbon dioxide and wastes are drawn from the body tissue into the capillary vessel. Arteries—transport blood away from the heart.
What are the different types of capillary electroseparation?
There are six types of capillary electroseparation available: capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), micellar electrokinetic capillary chromatography (MEKC), capillary electrochromatography (CEC), capillary isoelectric focusing (CIEF), and capillary isotachophoresis (CITP).
How is fluid exchange controlled in capillaries?
Fluid exchange is controlled by blood pressure within the capillary vessel (hydrostatic pressure) and osmotic pressure of the blood within the vessel. The osmotic pressure is produced by high concentrations of salts and plasma proteins in the blood.