Patent ID: 7141676

Claim:
A composition of matter, which comprises a discrete biotin-containing compound of the general structural formula: C-(L-P-B) n wherein, C is a multifunctional cross-linking moiety having discrete size and containing n substituents, which are reactive, or can be made reactive, with L; L is a water-soluble linker moiety of discrete size containing 6 to 50 atoms in length and is one or more of alkyl, heteroalkyl, aryl, and heteroaryl linker moieties containing one or more of ethers, hydroxyls, amines, thioethers, thiols, esters, maleimides, iodoacetamides, hydroxyl amines, acyl hydrazines, carboxylic acids, polyphosphoric acids, phenols, sulfonic acids, iodoacetamides, aldehydes, nitrophenylazides, polylysines, ammoniums, amides, ketones, decaboranes, dodedaboranes, boranes, closo-carboranes, or nido-carboranes; P is a biotinidase protective group that blocks biotinidase activity and is one or more of α-amino acids, N-methyl moieties, α-alkyl moieties, or aryl moieties; B is selected from biotin moieties; and n ranges from 3 to 64; wherein said composition of matter is selected from the group consisting essentially of: