This invention refers to an antibody or an antigen binding portion thereof, that binds specifically to human corneal endothelial cells (hCENCs), wherein the target of the monoclonal antibody, or antigen binding portion thereof, is essentially cell surface-expressed Peroxiredoxin-6 (Prdx6), as well as to methods for determining suitability of a cell sample for corneal transplantation, for quantitative enrichment of human corneal endothelial cells from a mixture of cells, and for isolating human corneal endothelial cells from a mixture of cell.