How was the first DNA fingerprint produced? This resulted in thousands of pieces of DNA with a variety of different lengths. These pieces of DNA were then separated according to size by a process called gel electrophoresis : The DNA was loaded into wells at one end of a porous gel, which acted a bit like a sieve. An electric current was applied which pulled the negatively-charged DNA through the gel. The shorter pieces of DNA moved through the gel easiest and therefore fastest.
It is more difficult for the longer pieces of DNA to move through the gel so they travelled slower. As a result, by the time the electric current was switched off, the DNA pieces had been separated in order of size.
The smallest DNA molecules were furthest away from where the original sample was loaded on to the gel. Next the nylon membrane was incubated with radioactive probes. Probes are small fragments of minisatellite DNA tagged with radioactive phosphorous.
The probes only attach to the pieces of DNA that they are complementary to — in this case they attach to the minisatellites in the genome. The minisatellites that the probes have attached to were then visualised by exposing the nylon membrane to X-ray film.
When exposed to radioactivity a pattern of more than 30 dark bands appeared on the film where the labelled DNA was. Another difference between gene sequencing and DNA fingerprinting is that gene sequencing reveals the nucleotide sequence of a gene while DNA fingerprinting reveals the pattern of STRs of a particular locus of an individual.
Gene sequencing identifies new alleles and diseased genes while DNA fingerprinting identifies individuals. This is also an important difference between gene sequencing and DNA fingerprinting.
Gene sequencing is a method which identifies the nucleotide sequence of a gene. It helps in the identification of diseased genes or new forms of genes called the alleles. On the other hand, DNA fingerprinting is a method we use in order to obtain the pattern of STRs at a particular locus of the genome. Since STR pattern is unique to a particular individual, it helps in the identification of individuals. Therefore, the main difference between gene sequencing and DNA fingerprinting is the type of information they help to obtain and their importance.
What are the differences between dna fingerprinting and dna profiling? Linica Uday. Nov 22, Explanation: DNA profiling uses repetitive sequences that are highly variable in particular short tandem repeats. Related questions How can dna profiling be misused? DNA profiling detects lots of minisatellites in the genome to produce a pattern unique to an individual.
This is called a DNA fingerprint. The probability of having the same DNA fingerprint between two people is very rare. Therefore, just like an actual fingerprint, the DNA fingerprint is unique to a person. DNA profiling usually involves the sampling of DNA and comparing it with a sample found at a crime scene.
Then the restriction enzymes are used to cut the DNA. Next, the resultant pieces of DNA sizes are separated using gel electrophoresis. Once the DNA pieces are sorted out in the gel, they will transfer to a nylon membrane to produce single strands of DNA. The nylon membrane is incubated with radioactive probes. The probes are minisatellites. They only attach to pieces of DNA that are complementary.
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