ABSTRACT
The major orientation of the laboratory is that of the biology of cells of immunologic interest. In these studies, liposomes have been of considerable value, because they have permitted construction of a number of model systems for ligand-cell interaction. The water-soluble fluorophore carboxyfluorescein (CF) encapsulated in liposomes is used as a means of measuring their interaction with the cell surface; bound liposomes are easily quantitated by bulk fluorometry or flow microfluorometry. The use of CF as a liposome marker has historically caused some problems of interpretation because of its apparent rapid release from liposomes and its apparent uptake into cells in free form. The stability and covalent nature of the bond between liposomes and protein was confirmed by taking the liposome peak. The advantage of a system using normal lymphoid cells is the large number of monoclonal antibodies available, in particular for structures encoded by genes mapping to the major histocompatibility complex of the 17th chromosome.
