DNA Profiling and Gel Electrophoresis

Biology Accelerated 2006

Biotechnology Genetics

Some slides taken and edited from Maria Hall, Julie Basil and Karen Wolfe

Think Pair Share

What is DNA profiling? How is DNA profiling used? How is the process performed?

Commonly Used Techniques

Each of the following will be explained in further detail Restriction enzymes Recombinant DNA (using plasmids) Gel electrophoresis DNA profiling DNA sequencing

Restriction Enzymes “molecular scissors”

Enzymes found in bacteria Used by the bacterium as a defense against

“foreign” DNA Cut DNA at very specific places or

sequences (called restriction sites) The “cut” DNA pieces can have either

Blunt ends Sticky ends

Restriction Enzymes

also known as restriction endonucleases

named for the bacteria where they originally came from ex: EcoRI

Why cut DNA?

DNA is cut so that another piece of DNA can be inserted

The “other” DNA contains the gene you want to copy

Citation Greatest Discoveries with Bill Nye: Genetics. Discovery Channel School. 2005. unitedstreaming. 23 January 2006 <http://www.unitedstreaming.com/>

Citation (MLA)Biologix: Manipulating DNA. United Learning. 1997. unitedstreaming. 23 January 2006 <http://www.unitedstreaming.com/>

How restriction enzymes work

cut each DNA strand at different bases--creates “sticky ends”

open “flap” of DNA can readily bind with a complementary “flap”

some restriction enzymes make “blunt ends”

RFLPs

abbreviation pronounced “rifflips” stands for restriction fragment length

polymorphisms restriction fragment =

fragment of DNA cut with restriction enzymes

length polymorphisms = many different lengths

Gel electrophoresis

Gel electrophoresis

technique used to separate strands of DNA, RNA or protein according to their size

For DNA, samples first need to be purified and cut with restriction enzymes

DNA placed into a well at one end of an agarose gel (like jello)

the gel acts as a strainer

Citation Greatest Discoveries with Bill Nye: Genetics. Discovery Channel School. 2005. unitedstreaming. 23 January 2006 <http://www.unitedstreaming.com/>

Electrophoresis animation

Electrophoresis Animation Electrophoresis Animation 2

http://www.bbc.co.uk/education/asguru/biology/04genesgenetics/04geneticcode/01geneticengineering/02isolatinggenes/index.shtml

http://www.shsu.edu/~chm_tgc/sounds/flashfiles/GE.swf

Self Check and Review

In your study group of 3 students discuss the following issues form a consensus and write down what you learned: DNA Profiling

Why is it done? What are its uses? What is needed to do DNA profiling (materials). How is it done? (steps in the process)

PCR ClipCitation (MLA)Biologix: Manipulating DNA. United Learning. 1997. unitedstreaming. 23 January 2006 <http://www.unitedstreaming.com/>

Citation (MLA)Biologix: Manipulating DNA. United Learning. 1997. unitedstreaming. 23 January 2006 <http://www.unitedstreaming.com/>