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Biotechnology. Applications and Basic Technology. Recombinant DNA technology. Recombinant DNA technology : set of techniques for recombining genes from different sources and transferring into cells where it may be expressed. Restriction Enzymes.
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Biotechnology Applications and Basic Technology
Recombinant DNA technology • Recombinant DNA technology: set of techniques for recombining genes from different sources and transferring into cells where it may be expressed
Restriction Enzymes • Occur in bacteria where they protect against intruding DNA • Involves restriction; foreign DNA is cut into small segments • Cut at specific points on small segments called specific recognition sequences • Several hundred restriction enzymes & ~ 100 different specific recognition sequences • Cuts DNA in staggered manner, resulting in single-stranded ends, called sticky ends
Creates restriction fragments • Used in lab to join DNA pieces from different sources • Temporary bonds held by weak H bonds • Can be made permanent by adding DNA ligase
Gel Electrophoresis • used to separate either nucleic acids or proteins based upon molecular size, charge and other physical properties • used to identify segments by looking at banding pattern when cut with restriction enzymes • DNA fragments can be isolated, purefied, and then recovered from gel
Electrical current is used to move charged particles at different rates
RFLP Analysis (restriction fragment length polymorphisms) • gel electrophoresis of restriction fragments results in characteristic banding pattern • Each band corresponds to DNA restriction fragments of certain length • Different alleles of gene result in dissimilar banding patterns • Similar patterns result when noncoding segments of DNA are used as starting materials
Fragments move different distances based on base pair length, size (how compact)
Recombinant DNA • Use restriction enzymes to alter DNA • Incorporate DNA into new organism to create a GMO (genetically modified organism) • Ex: Super Salmon, FlavrSavr Tomato • Super Salmon ABC Special
Polymerase Chain Reaction • Technique used to amplify (copy many times) DNA in vitro (inside the cell) • 1. DNA is incubated with special primers & DNA polymerase • 2. billions of copies of the DNA are produced in a few hours • 3. PCR is highly specific; primers determine sequence to be amplified • 4. only minute amounts of DNA are needed