Genetic Fingerprinting Flashcards
What do introns contain repetitive sequences of?
DNA called core sequences that have a unique pattern
What is more similar in more closely related individuals?
The core sequences
The making of a genetic fingerprint consists of what 5 stages?
Extraction, digestion, separation, hybridisation and development
What is involved in extraction?
The DNA is extracted from a sample e.g hair or blood and its quantity is increased using the PCR
What is involved in digestion?
The DNA is cut into fragments using restriction endonucleases
What is involved in separation?
The fragments of DNA are next separated according to size by gel electrophoresis using an electrical voltage. The gel is then immersed in alkali in order to separate the double strands into single strands
In separation, once the single strands have been produced, what are they transferred onto and by what technique?
They are transferred on to a nylon membrane by a technique called southern blotting
What occurs during hybridisation?
Radioactive DNA probes are now used to label the fragments and bind with the specific core sequences
What occurs during development?
A membrane with radioactively labelled DNA fragments is placed onto an x-Ray film. The development of this film reveals dark bands where the radioactive DNA probes have attached
Name 3 uses of genetic fingerprinting?
Forensic science, paternity tests and in determining genetic variability within a population
What is genetic fingerprinting and what is it based on?
It is a diagnostic tool used widely in forensic science and is based on the fact that the DNA of every individual, except twins is unique
