Ultrastructural studies of human and rabbit alpha-M-globulins.

Electron micrographs of isolated human alpha(2)M-molecules, obtained by the negative contrast technique, revealed morphologically homogenous structures resembling a graceful monogram of the two letters H and I. The modal values for the length and width of the alpha(2)M particles were 170 A and 100 A, respectively. Purified rabbit alphamacroglobulins contained about 80% alpha(1)M- and 20% alpha(2)M-globulins.

The ultrastructure of normal and pathological IgM immunoglobulins.

Free IgM immunoglobulins were examined in the electron microscope using the negative contrast technique. Normal human and rabbit IgM and Waldenström macroglobulins were indistinguishable from one another and revealed flexible spider-like particles with five appendages joining a central ring. The average total span of the molecules was 300 A.

Ultrastructure of gamma-M immunoglobulin and alpha macroglobulin: electron-microscopic study.

Electron microscopy of purified Waldenström macroglobulins and normal human and rabbit gammaM immunoglobulins revealed spider-like structures with five legs varying in length and often joining a central ring. Usually only the central more rigid part of this structure (about 150 by 170 angstroms) was clearly visible, but occasionally particles were seen with longer very flexible legs having a total span of about 350 angstroms. Molecules of gammaM antibody retained antibody activity during preparation for electron microscopy.