The present invention provides compounds of the formula X--R.sup.1-D-[Dpr, Orn or Lys](A)-R.sup.2(Z)-D-[Dpr, Orn or Lys](B)--R.sup.3(Y)--NR.sup.4R.sup.5; or R.sup.1(X)-D-[Dpr, Orn or Lys](A)-R.sup.2(Z)-D-[Dpr, Orn or Lys](B)--R.sup.3(Y)--NR.sup.4R.sup.5, in which X is a hard acid cation chelator, a soft acid cation chelator or Ac--, R.sup.1, R.sup.2 and R.sup.3 are independently selected from a covalent bond or one or more D-amino acids that can be the same or different, Y is a hard acid cation chelator, a soft acid cation chelator or absent, Z is a hard acid cation chelator, a soft acid cation chelator or absent, and A and B are haptens or hard acid cation chelators and can be the same or different, and R.sup.4 and R.sup.5 are independently selected from the group consisting of hard acid cation chelators, soft acid cation chelators, enzymes, therapeutic agents, diagnostic agents and H. The present invention also provides methods of using these compounds and kits containing the compounds.