Paraffin sections (4 μm thickness) of formalin-fixed human pancreases and isolated human islets were treated with 0.05% pronase for antigen retrieval. HS and Col18 HSPG core proteins were detected immunohistochemically using 10E4 anti-HS (US Biological/Amsbio) and anti-Col18 (Santa Cruz), respectively, with horseradish peroxidase-conjugated rabbit anti-mouse Ig (Dako). Background staining was checked using the corresponding isotype control Ig instead of the primary antibody. 3-amino-9-ethylcarbazole (AEC) was used as the chromogen. For morphometry, stained sections were imaged using a light microscope with attached camera (Olympus BX41). Image J software with color deconvolution plugin was used for the quantitative analysis of the % of islet area stained