Cellular heterogeneity in non-immune IgG-binding in a strain of Streptococcus mitis

Electron microscopy revealed that Streptococcus mitis ATCC 903 bound gold probes conjugated with goat IgG by non-immune mechanisms. Only a few of the cells and the cell wall fragments could bind IgG, in contrast to Staphylococcus aureus and Streptococcus group G which showed a more homogenous binding to nearly all cells or cell wall fragments.