PCR and Electrophoresis

Techniques of Recombinant DNA Technology

Multiplying DNA in vitro: The Polymerase Chain Reaction (PCR)

VIDEO CLIP◦Large number of identical molecules of DNA

produced in vitro◦Critical to amplify DNA in variety of situations

Epidemiologists use to amplify genome of unknown pathogen

Amplified DNA from Bacillus anthracis spores in 2001 to identify source of spores

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Techniques of Recombinant DNA Technology

Multiplying DNA in vitro: The Polymerase Chain Reaction (PCR)◦Repetitive process consisting of three steps

Denaturation Priming Extension

◦Can be automated using a thermocycler

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Polymerase chain reaction (PCR)

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Figure 8.5a

Polymerase chain reaction (PCR)

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Figure 8.5b

Techniques of Recombinant DNA Technology

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Techniques of Recombinant DNA Technology

Separating DNA Molecules: Gel Electrophoresis and the Southern Blot◦Gel electrophoresis

Separates molecules based on electrical charge, size, and shape

Allows scientists to isolate DNA of interest Negatively charged DNA drawn toward positive electrode Agarose makes up gel; acts as molecular sieve Smaller fragments migrate faster and farther than larger

ones Determine size by comparing distance migrated to

standards

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Gel electrophoresis

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Figure 8.6

GEL ELECTROPHORESIS VIDEO

Video of our lab’s gel electrophoresisElectrophoresis Results video

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