A simple fluorescent method to determine complement-mediated liposome immune lysis.

A simple inexpective method is described to study the kinetics of complement-mediated immune lysis of liposomes containing sheep red blood cell lipid antigens. It is based on the fact that trapping the fluorescent molecule 1-aminonaphthalene-3,6,8-trisulfonate and the dynamic quencher, alpha, alpha'-dipyridinium p-xylene dibromide within the liposome inner volume results in an extinguished fluorescence signal. On addition of helmolysin plus active complement, liposome lysis occurs. The exit of the fluorophore and quencher and their subsequent dilution in the external volume abolishes the quenching, resulting in a high fluorescence signal. The details of the method are described as well as the initial kinetic results.