See it in action!
CE used in Forensic Case:
A Beckman Coulter Capillary Electrophoresis costs at the least $34,000 (Intrsuments from different manufactureres and with different capabilities will cost more)
**Bare fused silica capillaries can cost anywhere from $37 to $145!
SU doesn't have a Capillary Electrophoresis instrument yet, but here's an example of one!
Click the block diagram to see an animation of how Capillary Electrophoresis works!
Applications of Capillary Electrophoresis
- small ions
- amino acids
- nucleic acids
The buffer cations form a double layer along the capillary surface.
The sample is carried through the capillary by an electroosmotic flow.
-very small sample size (nL)
-lower startup costs
How does the sample travel?
The ends of the capillary are placed into the buffer solutions to fill the capillary tubing. The end of the capillary that is farthest from the detector is placed into the sample solution until the sample has traveled a few inches above the detector solution. The tube is then placed back into the buffer with the electric voltages applied to the buffer solution to allow the sample to separate.
Click on the picture to see a comparison of
a micropipett tip and capillary tubes (96 tubes)
CE used around 4:30 min
Capillary Electrophoresis Seperation Techniques
Capillary Zone Electrophoresis (EZ): based on the difference in the charge-to-mass ratio of the analytes
Gapillary Gel Electrophoresis (CGE): when the charge-to-mass ratio is close size matters
Capillary Isoelectric Focusing (CIEF): As long as a molecule is charged it will migrate. The molecules will hault at the isoelectric point.
Isotachophoresis (ITP): Relies on zero electroosmotic flow. Anions and cations can be determined but in separate runs.
Electrokinetic Chromatography (EKC): Allows the separation of ciral compounds
Micellar Electrokinetic Capillary Chromatography (MECC): Relies on a robust and controllable electroosmotic flow. Resembles reverse-phase LC with the benefits of CE.
Micro Emulsion Electrohinetic Chromatography (MEEKC): Solutes partition with moving oil droplets in buffer. Allows separations of aqueous and water-insoluble compounds.
Non-Aqueous Capillary Electrophoresis (NACE): Separation in a medium composed of organic solvents.
Capillary Electrochrmatography (CEC): couples high separation efficiency of CZE and HPLC
Link is an example of a DNA sequencing CE
Sample Vial: conatins the sample liquid to be used
Source/Destination Vials: the source vial contains the buffer solution and the destination vial is the waste vial
Capillary: filled with fused silica to separate the sample
Electrodes: add the voltage to the buffers to separate the charged particles
High Voltage Power Supply: this supplies the voltage to the electrodes
Detector: qualitates the data from the capillary
Data Output: the computer system that is used to retrieve the data from the detector.
Click here for an article comparing gel & capillary electrophoresis!
A technique which performs high efficiency separations of molecules by the use of high voltages, which create electroosmotic flow.
Applied Biosystems 3500 Series Genetic Analyzers for DNA Sequencing and Fragment Sizing
Tags: 3500, Series, Genetic, Analyzers, DNA, Sequencing, Applied, Biosystems, Life, Technologies
Ohio University Forensic Chemistry Lab, DNA Analysis
Tags: forensic, science, chemistry, DNA, STR, genetic, analysis, capillary, electrophoresis, PCR, profiler, plus, crime, scene, CSI