WWLPT

"Fishing for Microsatellites"|

PCR Demo

Put your goggles on and transfer the DNA sample to the 72^oC water bath and leave it there for 90 seconds.  Remove your goggles.

Discussion

Lead your student hypothesis formation and discussion to the fact that the higher temperature the DNA polymerase (from a thermophilic bacteria now) ‘Extends’ or attaches complementary DNA nucleotides to the exposed DNA strands.  These sequences begin where the primers end and run to the end of the segment being extended.

Chalkboard

Draw the primers with the extended nucleotides still attached to the original DNA strand.  It might help to have drawn the primers and their attached nucleotides in a different color than the original strand of DNA.  The reason why should become apparent by the end of this cycle.

5’ ATCGCTTACGTCAACT 3’        original strand
3’ TAGCGAATGCAGTT     5’         primer strand

5’      CGCTTACGTCAACT 3’        primer strand
3’ TAGCGAATGCAGTTGA 5’        original strand

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