immunofluorescent staining of bacteria using fluorescein-labeled antibody to the third component of complement showed that streptococci incubated in fresh serum bound complement evenly over the entire cell surface , whereas streptococci incubated in fresh plasma or in serum plus fibrinogen fluoresced only at some of the cross-walls between adjacent daughter cocci and at occasional terminal cocci .
C0009498
complement
C0229671
serum