The method employed by Elucigene QST*R kits is the QF-PCR (Quantitative fluorescence-Polymerase Chain Reaction) technique. Using PCR amplification, fluorescent dye labelled primers target highly polymorphic regions of DNA sequence, short tandem repeats (STRs), that are located on the chromosomes of interest. Each targeted STR marker is specific to the chromosome on which it is located, thus the copy number of the STR marker can be diagnostic of the copy number of the chromosome.
A normal sample has the normal complement of two of each of the autosomal chromosomes and two sex chromosomes, thus two alleles of a chromosome specific STR are determined by the QF-PCR technique as two peaks in a 1:1 ratio. The QF-PCR observation of an extra STR allele as either a three peak pattern in a 1:1:1 ratio or two peak pattern in a 2:1 peak ratio is diagnostic of the presence of an additional sequence which in turn may represent an additional chromosome, as in the case of a trisomy.
QF-PCR - For more information on the Elucigene QF-PCR technique please go to the download section.
