IEM of abdominal fat aspirates from patients with different amyloid diseases. Postembedding immunostaining with polyclonal anti-λ light chains (A), anti-k light chains (B), and monoclonal anti-SAA (C) and polyclonal anti-TTR (D) antibodies. Secondary antibodies are conjugated with gold particles 15 nm in diameter. Uranyl acetate, lead citrate. Scale bar, 1 μm.