Statistics and Data Analysis for Microarrays Using R and Bioconductor, 2nd Edition

54 St at ist ics and Data Analysis for Microarrays Using R and Bioconductor

ACGTGCAATGCCGTACGGCA

C

gene A

A

C

G

T

G

C

A

A

T

G

C

C

G

gene A

match

mismatch

A

C

G

T

G

C

G

A

T

G

C

C

G

mismatch

The hybridization happens at a

critical temperature when the PM hybridizes

and even a single mismatch prevents the MM

from hybridizing.

FIGURE 3.11: The principles of the Affymetrix technology. The probes cor-

respond to sho rt oligonucleotide sequences thought to be representative for

the given gene. Each oligonucleotide sequence is repres e nted by two probes:

one with the exa ct se quence of the chosen fragment of the gene (perfect match

or PM) and one with a mismatch nucleotide in the ...