Indirect immunostaining of formalin-fixed paraffin embedded human tonsil section with anti-κ light chain (dilution 1 : 200; red) and rabbit anti-λ light chain (cat. no. 349 003, dilution 1 : 200; green). Immunoreactive structures on B-cells have been revealed with fluorochromated secondary antibodies. Nuclei have been visualized by DAPI staining (blue).