Using AFM to Characterize DNA

Introduction
DNA microarrays have proven to be
invaluable tools in both clinical and
research settings for gene expression
analysis, genotyping and to identify
mutants in cell populations or tissue
samples because they enable highly
parallel analysis of thousands of
individual DNA sequences [Heller
2002]. Each microarray can contain
tens of thousands of unique probes
per cm2 which are used to characterize
biological samples in a multiplexed
manner. In a typical assay, biological
targets are isolated, tagged with a
fl uorescent dye and then introduced to
the probes on the microarray surface
where hybridization reactions occur
between complimentary probes
and targets. After the hybridization
reactions are complete, microarrays
are generally read in a laser-based
fl uorescent scanner to identify
and quantify the number of probe –
target duplexes.