Complement enhances the neutralization of virus by antibody. This is acheived by increasing the size of the virus antibody complex and by producing incorporation of C3b into complexes which can then bind to receptors on phagocytic cells. Antibody and complement can directly lyse those viruses with lipid envelopes. Antibody and complement can kill virus infected cells in vitro. A variety of human cell lines infected with viruses which contain surface antigens are lysed by human serum if both antibody and functional complement are present.
Advantage is the use of single tagged reagent for many antibodies.
This test can reveal a small number of infected cells within an organ or within a population of cells. Can also be used to localize virus within the cell.