On electron microscopy amyloid characteristically exhibits -

The AL (amyloid light chain) protein is produced by plasma cells and is made up of complete immunoglobulin light chains, the amino-terminal fragments of light chains, or both. For unknown reasons, only a few types of immunoglobulin light chains are prone to forming aggregates. As expected, the deposition of amyloid fibril protein of the AL type is associated with some form of monoclonal B cell proliferation. Defective degradation has also been invoked as the basis for fibril formation, and perhaps paicular light chains are resistant to complete proteolysis. However, there are no sequence motifs peculiar to the immunoglobulin light chains found in amyloid deposits. Robbins 9 th edition page no. 153