A rapid method for the detection of circulating immune complexes in biological fluids by counterimmunoelectrophoresis

Owing to their great content in neuraminic acid and/or nucleic acids, most of the circulating immune complexes run significantly faster as unbound gammaglobulins during agar gel electrophoresis. Therefore, because of their immunoglobulin components they can be easily detected in the alpha-1, inter-alpha, alpha-2 and beta fractions with monospecific anti-Ig-sera by counterimmunoelectrophoresis. The presence of Factor III of complement and of fibrinogen, in some cryoglobulins can be proved in the some way. Finally, nucleic acid content (both RNA and DNA), and presence of neuraminic acid in precipitated immune complexes can be demonstrated by usual histologic methods (Giemsa, methyl green-pyronine, PAS or Aminoff) on washed and dried slides.