Figure 4

Study design. From a freshly resected colectomy specimen, three types of procurement were performed from tissue originating from the same site. In the fresh state, cells in Group 1 are exfoliated and enriched for using ber-Ep4(+) magnetic beads. The area from where these cells came from was then sectioned into 2 mirror pieces, with one fixed in formalin and the other frozen. For the latter two, colon cells were obtained by laser capture microdissection. After exfoliation, RNA was extracted in parallel from all the samples and afterwards underwent expression profiling on an Affymetrix microarray chip. The results were compared between the samples within each group and against the samples in other groups. EE = exfoliation/enrichment, FFPE = formalin fixed, paraffin embedded, LCM = laser capture microdissection, EP = expression profile assay.