The document discusses DNA primers used in polymerase chain reaction (PCR). Primers are usually about 20 nucleotides long and are designed to flank the region of DNA to be amplified. The melting point of a primer is determined by its G-C and A-T content, with the melting temperature calculated as 4°C times G-C content plus 2°C times A-T content. Primers are added in excess so they will bind to the target DNA rather than the DNA strands binding to each other. Taq polymerase, isolated from Thermus aquaticus, is used to amplify the DNA from the primers during PCR in the presence of magnesium.

6. TTAAGGCTCGA . . . . AATTGGTTAA
. . . .

8. 

9. TTAACGGCCTTAA . . . TTTAAACCGGTT
AATTGCCGGAATT . . . . . . . . . .>
and
<. . . . . . . . . . AAATTTGGCCAA
TTAACGGCCTTAA . . . TTTAAACCGGTT

10. 3’
5’3’
Target DNA
5’
forward
reverse

11. Usually about 20 nucleotides in length
Designed to flank the region to be amplified
Melting point determined by G-C and A-T content
Tm = 4oC (G+C) + 2oC (A+T)
Ex: a primer with 10 G/C and 10 A/T would have
a Tm of 60oC 4(10) + 2(10)=60oC
Target DNA
5’ 3’
3’ 5’

12. The primers are added in excess so they
will bind to the target DNA, instead of the
two strands binding back to each other.

14. Taq Taq produces an enzyme called
DNA polymerase, that
amplifies the DNA
from the primers by the
polymerase chain reaction,
in the presence of Mg.
T. aquaticus was first
isolated at Yellowstone.
The polymerase isolated from
T. aquaticus is commonly
called Taq polymerase