Quantitative Measurement of Guinea Pig Complement with Liposomes

Abstract

Liposomes were investigated as an alternative reagent to sheep erythrocytes for quantitative titration of whole complement activity. The liposomes were prepared with various concentrations of phospholipid and were sonicated for more effective dispersion. It was found that reproducible complement titrations could be performed with sonicated liposomes prepared with 1 or 2 µmol of phospholipid per milliliter of marker solution (0.3 M galactose). Electron micrographs of liposomes treated with complement and hemolysin showed no discrete lesions, but rather aggregates of liposome fragments.