Genetic profiling is where samples of DNA are collected and compared. If the DNA samples are found to be identical, it means they have either come from the same person or from identical twins.
Genetic profiling can also be called
- DNA profiling
- genetic fingerprinting
- genetic map
- DNA sequencing
Applications of DNA profiling include:
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for forensic reasons e.g. to identify a criminal in a murder case
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for medical reasons e.g. to predict breast cancer or deafness if this runs in a family
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to identify paternity or maternity e.g. if a baby is kidnapped and the birth mother wants to identify her own baby
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to identify if twins are identical or fraternal
- checking animal pedigrees
The Steps taken in Genetic Profiling can be summarised as:
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Extracting the DNA
A sample of cells is collected e.g. semen, blood, hair root. The DNA is extracted from the cells by breaking up the cells just as you do with the plant sample in class. -
Cutting the DNA
This is done using enzymes. The DNA is split up into segments by restriction enzymes. -
Gel Electrophoresis
The DNA segments are placed on a gel and an electric current is passed through the gel. Depending on the size of the segments a pattern develops - the smaller the segment the farther it travels. The DNA is transferred onto a nylon sheet. -
A Radioactive probe
This attaches onto the DNA segments. -
X-Ray
The DNA segments can be seen on an x-ray film as dark bands. It is this characteristic series of bands that shows the genetic profile of the individual. This profile is more accurate when more segment samples are taken.
Click here to go to create a profile.
You will have a series of instructions to tell you waht to do. Read them carefully.
DNA fingerprint
