Components of Polymerase Chain
Reaction (PCR)
Molecular Diagnostics
(MDx) Review 554
COMPONENT ROLE
Template DNA region to be amplified. From patient’s genomic or mitochondrial DNA or from
microorganisms.
2 oligonucleotide primers Short segments of ssDNA designed to hybridize to template strands & provide starting
point for synthesis of daughter strands. 1 designed to hybridize adjacent to region of
interest on 3’ end of 1 strand, other designed to hybridize adjacent to region of interest
on 3’ end of other strand. Segment to be amplified falls between 2 primers.
Thermostable DNA polymerase E.g.,Taqpolymerase. Extends primers on each template strand by adding dNTPs &
catalyzing formation of phosphodiester bonds.
Deoxynucleotide triphosphates (dNTPs) Building blocks from which DNA polymerase synthesizes a new strand of DNA: dATP,
dGTP, dTTP, dCTP.
