Figure 1.

Altered Sirius red staining on formalin-fixed paraffin-embedded (FFPE) tissue sections following exposure to heat-induced antigen retrieval (HIAR) conditions. (A) Sirius red single histochemical stains performed on serial FFPE tissue specimens under optimal conditions (no retrieval) and following exposure to higher temperatures under HIAR conditions (3, 5 and 10 min). (B) Image analysis of a representative portal region on serial sections highlights how increasing temperature alters the affinity of Sirius red staining and results in false-positive collagen expression (percentage of total analyzed area). Scale, 50 µm.