Immunoblot analysis.

Detection of IgA (A), IgG (B), and κ light chain (C) in soluble proteins of liver tissue probes. Immunodetection was performed on the soluble protein fraction of our patient (right) in comparison to control liver samples (left). After immunodetection, counterstaining of the spots was performed with CBB. (A) Monoclonal IgA heavy chain is detected by a set of well-resolved red spots characterized by charge microheterogeneity. (B) Polyclonal IgG heavy chains are observed as a “fuzzy” red zone, without distinct, individualized spots. (C) Monoclonal κ light chain corresponds to one dominant distinct red spot (spot 25) besides a “fuzzy” polyclonal background.