Using tissue array technology, each tissue sample is treated in
an identical manner. Like conventional formalin-fixed paraffin embedded
material, tissue microarrays are amenable to a wide range of techniques
including histochemical stains, immunologic stains with either chromogenic
or fluorescent visualization, in situ hybridization (including both
mRNA ISH and FISH), and even tissue micro-dissection techniques.
For each of these protocols, conventional sections can have substantial
slide to slide variability associated with processing 300 slides
(for example, 20 batches of 15 slides). The tissue microarrays allow
the entire cohort to be analyzed in one batch on a single slide.
Thus reagent concentrations are identical for each case, as are
incubation times and temperatures, wash conditions, and antigen
retrieval, if necessary.