US 6,143,513 A · Method and kit for detecting betalactam-containing compounds

Abstract

Methods and kits are disclosed for detecting betalactam-containing compounds in a sample, and typically liquid products intended for human consumption such as milk. Betalactam-containing compounds include the class of betalactam antibiotics which may be present as undesired contaminates of milk. The methods involves contacting the sample with a D,D-carboxypeptidase and a substrate having a carboxyterminal D-alanine-D-alanine to form a reaction mixture, wherein the D,D-carboxypeptidase is capable of cleaving the terminal D-alanine from the substrate to yield a cleaved substrate. In an optional step, the reaction mixture is further contacted with a ligand specific to the cleaved substrate or substrate. The cleaved substrate or substrate of the reaction mixture, or the ligand specific to the cleaved substrate or substrate, is then captured by a surface-bound binding partner, with the amount of captured material being indicative to the amount of betalactam-containing compound in the sample. Kits for performing the methods of this invention are also disclosed.

Claims30

Dependent claims

A method for detecting a betalactam-containing compound in a sample, comprising:

contacting the sample with a D,D-carboxypeptidase and a substrate having a carboxyterminal D-alanine-D-alanine to form a reaction mixture, wherein the D,D-carboxypeptidase is capable of cleaving the terminal D-alanine from the substrate to yield a cleaved substrate;
optionally contacting the reaction mixture with a ligand specific to the cleaved substrate or a ligand specific to the substrate to form a modified reaction mixture, wherein the ligand specific to the cleaved substrate is capable of binding to the cleaved substrate to form a ligand/cleaved substrate complex, and wherein the ligand specific to the substrate is capable of binding to the substrate to form a ligand/substrate complex;
and
capturing on a sensing surface (i) the cleaved substrate or the substrate of the reaction mixture, or (ii) the ligand/cleaved substrate complex or the ligand/substrate complex of the modified reaction mixture, or (iii) the ligand specific to the cleaved substrate or the ligand specific to the substrate of the modified reaction mixture, by a surface-bound binding partner thereto.

1 more element

Dependencies are inferred from the claim text.

Method and kit for detecting betalactam-containing compounds

Life of this patent

Method and kit for detecting betalactam-containing compounds

Life of this patent

Abstract

Claims30