What is capillary electrophoresis in DNA fingerprinting?
Capillary electrophoresis (CE) is an alternative to conventional slab gel electrophoresis for the separation of DNA fragments. The quantity of DNA required for separation is in the nanogram range. Single-base resolution can be obtained on fragments up to several hundred base pairs.
Can electrophoresis be used in DNA fingerprinting?
Gel electrophoresis is the process by which we take the DNA and run an electric charge through it, therefore we can use it to compare two DNA samples, hence the name DNA fingerprinting.
Why is capillary electrophoresis used for in forensic science?
Capillary electrophoresis (CE) is used in the ATF Forensic Science Laboratories for the analysis of inorganic ions commonly encountered in post-blast residues including monomethylamine (MMA) and benzoate ions. Monomethylamine nitrate is found in Tovex, a water gel explosive.
What is capillary electrophoresis How does it work?
Capillary electrophoresis is the technique of moving molecules through a tube structure using electric current. Each end of a capillary is in buffer, which is the vehicle used to carry studied molecules and neutralize the negatively charged capillary walls. Ions arrive at the cathode according to their size and charge.
How is electrophoresis similar to an individual’s actual fingerprints?
Gel electrophoresis separates molecules based on size and charge. Smaller DNA fragments move farther than long fragments of DNA. A specific restriction enzyme will always make the same set of DNA fragments for the same person, creating a recognizable “fingerprint” for that person.
What is capillary electrophoresis method?
Capillary electrophoresis, or CE, is a technique used in chemical analysis to separate molecules in an electric field according to size and charge. The molecules are then separated based on the difference in their velocity, which is influenced by charge, size, and the solvent’s viscosity.
How does DNA capillary electrophoresis work?
A sample containing fragments of DNA is injected into the capillary. This causes the DNA fragments to migrate on to the end of the capillary. Once the sample has been injected, the electric field is reapplied, to drive the DNA fragments through the capillary.
What is EOF 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. This flow is called electroosmotic flow.
What controls are used in capillary electrophoresis?
Capillary electrophoretic separations are usually performed at or close to room temperature (25°C). Temperature control, however, is important and separation capillaries are thermostated in an air or liquid bath. Thermostating is used to remove heat and to establish a constant temperature.
How is capillary electrophoresis used in DNA analysis?
Capillary electrophoresis is a high-throughput separation method commonly employed for DNA analysis owing to rapid analysis times and small sample volumes. Various modes of capillary electrophoresis, which are summarized in Table 1, are used depending upon the application.
Which is faster to generate a DNA fingerprint RFLP or PCR?
It is the unique combination of these polymorphisms in an individual that allows a profile to be generated. Note also, that capillary electrophoresis is commonly used to separate the resulting DNA fragments. Thus, PCR can produce a DNA fingerprint much faster than the RFLP method described above.
How are STR regions amplified in DNA fingerprinting?
In modern DNA fingerprinting STR regions within the nuclear DNA are amplified using the PCR method. The polymorphisms displayed at each STR region are by themselves very common, typically each polymorphism will be shared by around 5 – 20% of the population. However, as with RFLP analysis, investigators always examine multiple loci.
What was the first legal use of DNA profiling?
You will now test your understanding of DNA profiling by using a simulation that asks you to examine gel banding patterns in an effort to assign paternity. Interestingly, the first legal use of a “DNA fingerprint” was in a paternity case. Alex Jeffreys was asked to help in a disputed immigration case.