Abstract: A class of sulforhodamine labeling reagents capable of binding with a biomolecular species to produce a conjugate with fluorescent properties. The sulforhodamine labeling reagents have the structure: ##STR1## The group X is selected from an alkyl, an olefin, a monocyclic aliphatic saturated hydrocarbon, an aryl, or nothing at all. The group Y is selected from an amide, a substituted amide, or nothing at all. The group Z is selected from a monocyclic aliphatic hydrocarbon, an aryl, or an alkyl, as defined with respect to group X, a polyethylene glycol chain of the general form (CH.sub.2 CH.sub.2 O).sub.n, or nothing at all. The alkyl or polyethylene glycol chain may further have inert intermediate amide, ether, or disulfide functionalities. The group X, group Y, and group Z cannot all be nothing at all or non-existent. The group R is an electrophilic moiety suitable for conjugation of the fluorescent labeling reagent with a biomolecular species. Also disclosed is a method of making the reagents.

Abstract: The present invention is directed to a method for extending the length of one of the three linker arms of the compound of Formula I in the production of novel trifunctional antibody-like compounds. Formula I is defined as follows: ##STR1## wherein X is ##STR2## wherein k=1 or 0; wherein Z is ##STR3## wherein s=1 or 0; wherein n=1 or 0;wherein q=1 or 0;wherein Y is ##STR4## wherein Y' is ##STR5## wherein p or m may be the same or different and are integers ranging from 0 to 20 with the provisos that when n=0, the sum of m and p is an integer ranging from 1 to 20, whereas when n=1, p and m are each an integer that is at least 1 and the sum of p and m is an integer ranging from 2 to 20;wherein R.sup.1 is straight or branched chain lower alkyl having from 1 to 6 carbon atoms or lower alkoxy having from 1-6 carbon atoms; andwherein R.sup.