Abstract: The invention relates to a method for diagnosing a disease state mediated by pathogenic cells, said method comprising the steps of administering to a patient a composition comprising a conjugate or complex of the general formula Ab-X wherein the group Ab comprises a ligand that binds to the pathogenic cells and the group X comprises an imaging agent, and detecting the pathogenic cells that express a receptor for the ligand using mutiphoton in vivo flow cytometry.

Abstract: The present invention relates to producing more densely functionalized indicator cells which along, with other components, can be used to detect the presence or absence of antibodies or antigens, by using the A, B, AB and MNS antigens which have a greater degree of expression than the conventionally used D antigen to label the indicator cells with IgG. The present antigen systems have levels of expression that approach one million antigens per cell, which is in great contrast to the conventional D antigen sites of about 10,000-30,000 antigens per cell. This marked increase in the antigen systems level of expression could produce a boost in the kinetics and the magnitude of the binding of the indicator cell to the solid phase, which improves assay performance.

Abstract: The invention relates to a method for diagnosing a disease state mediated by pathogenic cells, said method comprising the steps of administering to a patient a composition comprising a conjugate or complex of the general formula Ab-X wherein the group Ab comprises a ligand that binds to the pathogenic cells and the group X comprises an imaging agent, and detecting the pathogenic cells that express a receptor for the ligand using mutiphoton in vivo flow cytometry.