Neomarker rb 9013 p1

Oral biopsies were fixed en bloc in 10% neutral buffered formalin, embedded in paraffin, sectioned, mounted, and stained with H&E according to standard laboratory protocols. Immunohistochemistry was performed on 4‐µm thick, formalin‐fixed, paraffin‐embedded tissue sections, as previously described, with antigen retrieval performed in Dako Target Retrieval Solution (S1699) for 30 minutes at 95°C 1. Primary antibodies and dilutions were: rat anti‐CD3 (clone 3–12, diluted 1:10, Leukocyte Antigen Biology Lab, UCD); and rabbit anti‐CD20 (NeoMarker RB‐9013‐P1; 1:300; Thermo Fisher Scientific, Pittsburgh). Sections were then incubated with a Streptavidin‐HRP label (anti‐rabbit link, or anti‐rat link; Biocare Medical's 4+ Detection System GR608, or GR607 and HP604, respectively). Detection was visualized with Vector NovaRED for peroxidase (SK‐4800), per manufacturer's instructions. Sections were counterstained in Mayer's hematoxylin. Nonspecific background was evaluated with duplicate sections that received diluent in place of the primary antibody. Biopsies were interpreted by a board‐certified veterinary pathologist (NV).