Abstract: The invention relates to the fields of materials sciences and medicine and relates to an agent, which can be used, for example, as a contrast medium for the localization of cancer cells. The object of the present invention is to disclose an agent which sensitively and selectively recognizes the site and the type of the molecules or cells to be examined. The object is attained through an agent composed at least of bio-shuttle molecules to which endohedral fullerenes are coupled by way of peptide-based molecules, wherein the endohedral fullerenes are hydrophobic and correspond to the formula A3-xMxZ@C2n in which x=0 to 3 and n?34, A means rare earths and/or transuranic elements, M means metals, Z means non-metals and C means carbon. The object is further attained through a method in which hydrophobic endohedral fullerenes are coupled with bio-shuttle molecules by way of an irreversible Diels-Alder reaction with an inverse electron demand (DARinv).

Abstract: The present invention relates to conjugates for mediating a cell-specific, compartment-specific or membrane-specific to methods of active substances. The invention also relates to methods of preparing these conjugates as well as their use. The conjugates comprise: a transport mediator for the cell membrane, a cell-specific, compartment-specific or membrane-specific address protein or peptide, and an active substance to be transported.

Abstract: A method of discriminating between specific antibodies in samples of sera or other body fluids from humans or other primates containing antibodies arising from infection with HTLV-I, containing antibodies arising from infection with HTLV-II or containing antibodies arising from infection with related retroviruses, is described. In said method, the sample to be analyzed is subjected to at least four immunoassays, each using a different diagnostic antigen selected from four defined groups of peptides. Additionally, an immunoassay kit adapted for said method of discrimination, new peptides and a method of detecting antibodies with said peptides, are described.