CD4 and CD8 expression on sarcoid T-cells. Cryostat sections from a lymphocyte rich area of sarcoid tissue dual stained with different combination of rabbit anti-CD3 and monoclonal mouse anti-equine CD4 or equine CD8α. A–C Frozen tissue sections dual labelled with (A) rabbit anti-CD3 (texas red), (B) mouse anti-CD4 (FITC) (C) combined image with DAPI nuclear counterstain, most cells express both CD4 and CD3 although some CD4 only cells are present (green arrow). D–F Frozen tissue sections dual stained with (D) rabbit anti-CD3 (texas red), (E) mouse anti-CD8 (FITC), (F) combined image with DAPI counterstain most cells express both CD3 and CD8 although some CD3 only cells are present (red arrow). G–I Frozen tissue sections dual labelled with (G) monoclonal anti-CD8 TRITC and (H) anti-CD4 FITC (F) combined image with DAPI nuclear counterstain, the majority of cells are CD4 CD8 dual positive with a few CD8 and CD4 single positive cells (red and green arrows respectively).