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Restriction Fragment Length Polymorphism ( RFLP ). By Jerikka , Kiara and Nick. Introduction. “Any difference in DNA sequence, coding or non-coding, that can be detected between individuals.”. Let’s talk about POLYMORPHISM. Organisms of same species carry same genes, different alleles
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Restriction Fragment Length Polymorphism(RFLP) By Jerikka, Kiara and Nick
Introduction “Any difference in DNA sequence, coding or non-coding, that can be detected between individuals.” Let’s talk about POLYMORPHISM • Organisms of same species carry same genes, different alleles • Genomes of individuals from same species are POLYMORPHIC (unless identical twins)
What is Restriction Fragment Length Polymorphism (RFLP)? Definition -RFLP are differences in homologous DNA sequences detected by presence of fragments with varying lengths after digestion of DNA. -RFLP is molecular marker specific to single restriction enzyme combination. -Usually RFLP markers are co-dominant meaning both alleles will be detected in heterozygous sample.
Definition What is it used for? • Used in genome mapping and variation analysis. • Used when someone wants a paternity test to see someone’s parents or relatives • Used to find hereditary diseases (Huntington’s disease) or in forensics to solves crimes (Matching DNA)
Explanation 3. Single stranded DNA’s migrate from gel to nylon membrane. (Southern Blotting) - Nylon membrane is soaked in solution with radioactive complementary probes. 2. Fragments appear as smear. Gel placed against nylon membrane and put inm denaturing solution. 1. Sample of DNA extracted and put on gel.
Explanation 5. Radioactive probes burn the image in the X-ray film 4. Radioactive probes anneal at specific locations. Nylon membrane against an X-ray 6. Now you have an autoradiogram.
WAIT!…SOUTHERN BLOTTING?! • A procedure allowing DNA in electrophoresis gel to be transferred to nylon membrane. • Maintaining position of DNA band fragments.
What is an autoradiogram? • Gel pattern imprinted on X-ray film by radioactive probe. • Each individual is different with a special pattern. • Special pattern can be used to match DNA.
Application When is it used? Where is it used? • Genotyping • Forensics • Paternity tests • Patterns in hereditary diseases • Families can find out who are at risk for the disease and who are carriers • Used in laboratories and hospitals • Little FYI… • RFLP is slow, tedious and requires large amounts of DNA • Use Polymerase Chain Reaction because its quicker
Helpful Diagrams! RFLP helps us see the differences between the DNA!
Who discovered this? Alec Jeffrey in 1985 http://www.directgene.com/guide/history_of_rflp