By a News Reporter-Staff News Editor at Biotech Week -- Data detailed on Immunology have been presented. According to news originating from Newark, Delaware, by NewsRx correspondents, research stated, "Although detection of natural haptens by antihapten antibodies in sandwich assay format has the theoretical advantages of high analytical specificity and sensitivity, this type of assay has not been reported because of the seemingly insurmountable task of avoiding steric hindrance between the 2 bindings. This is especially true for ring-structured hydrophobic haptens."
Our news journalists obtained a quote from the research from Siemens, "The macrolide drug tacrolimus (FK506, Prograf ®, 804 Da) is such a hapten. Here we show the detection of tacrolimus using 2 antitacrolimus monoclonal antibodies in a sandwich assay. Both antibodies were developed by use of an intact tacrolimus molecule covalently linked to a carrier protein but via 2 different positions separated by 10 carbon atoms. Epitope analysis based on drug analog binding was used to show no overlap between the binding sites of the 2 antibodies, indicating the 10-carbon separation resulted in 2 distinct epitopes. The distinct epitopes suggested that the drug might be approachable by the antibodies from 2 separate directions, which predicted simultaneous binding as in sandwich formation. This prediction was confirmed in sandwich ELISA and affinity column-mediated immunoassay formats. The assay demonstrated good imprecision and significantly lower metabolite cross-reactivity than competitive assay counterparts. Comparison with liquid chromatography-tandem mass spectrometry (LC-MS/MS) using 55 whole-blood samples from transplant patients with tacrolimus concentrations ranging from 0.9 to 29.5 ng/mL showed a linear regression: sandwich = 0.99 X LC-MS/MS + 0.10 ng/mL, r = 0.991, S-y vertical bar x = 1.08 ng/mL."
According to the news editors, the research concluded: "This work demonstrates that a highly specific sandwich assay using 2 antihapten antibodies is feasible for the measurement of a hapten drug."
For more information on this research see: Sandwich Assay for Tacrolimus Using 2 Antitacrolimus Antibodies. Clinical Chemistry, 2014;60(4):621-630. Clinical Chemistry can be contacted at: Amer Assoc Clinical Chemistry, 2101 L Street NW, Suite 202, Washington, DC 20037-1526, USA (see also Immunology).
The news correspondents report that additional information may be obtained from T.Q. Wei, Siemens Healthcare Diagnost Inc, Newark, DE 19714, United States. Additional authors for this research include Y.F. Zheng, M. Dubowy and M. Sharma.
Keywords for this news article include: Antibodies, Antigens, Pharmaceuticals, Drugs, Newark, Therapy, Delaware, Epitopes, Immunology, Macrolides, Tacrolimus, United States, Blood Proteins, Immunoglobulins, Immunosuppressive Agents, North and Central America
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