[Advance of the examination of eosinophil: methodology and clinical significance--morphological examination--electron microscopic examination by immuno-SEM].

An index of IgG receptors on eosinophils by the use of immuno-SEM. The IgG (Fc) receptors on the eosinophils in hypereosinophilic patients were studied by the use of anti-IgG linked carboxylate modified latex particles. Eosinophils were separated into various cell densities by metrizamide discontinuous gradients. Eosinophils in each fraction were incubated with anti-IgG linked latex particles. Then eosinophils were observed by scanning electron microscopy. The number of latex particles attached to the eosinophils were considered to represent the number of IgG receptors in this study. The latex particles attached to the low density eosinophils were much more numerous than those attached to the high density eosinophils. This suggests that the number of IgG receptors on the eosinophils is correlated to the biological activity of eosinophils.