Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-10-30T20:38:41.045Z Has data issue: false hasContentIssue false

Development of a biosensor immunoassay for the quantification of αS1-casein in milk

Published online by Cambridge University Press:  14 January 2005

Stéphanie Muller-Renaud
Affiliation:
INRA, Unité de Recherches en Technologie et Analyses Laitières, Place du Champ de Foire, F-39800 POLIGNY, France
Didier Dupont
Affiliation:
INRA, Unité de Recherches en Technologie et Analyses Laitières, Place du Champ de Foire, F-39800 POLIGNY, France
Philippe Dulieu
Affiliation:
Université de Franche-Comté, Laboratoire de Biochimie, Biologie Cellulaire et Moléculaire, UFR Sciences et Techniques, F-25000 BESANCON, France

Abstract

An immunoassay to quantify αS1-casein (αS1-CN) in milk using an optical biosensor, based on surface plasmon resonance (SPR) measurement, has been developed. The assay consists of a two-step sandwich strategy, with two anti-αS1-CN antibodies directed against each extremity of the molecule. This strategy permits only intact αS1-CN to be quantified and not its degradation products. The calibration curve was obtained using a reference milk powder with a known αS1-CN concentration. Analysis time per sample was less than ten minutes. The antibody-coated surface could be used for more than 150 determinations. Detection limit was established at 0·87 μg/ml and the intra- and inter-assay variation coefficients were 2·86 and 5·31%, respectively. The method was applied to raw milk to quantify intact αS1-CN, with no pre-treatment of the sample. An initial analysis of 48 milk samples permitted αS1-CN concentrations ranging from 8·8 to 12·06 mg/ml to be obtained.

Type
Research Article
Copyright
Proprietors of Journal of Dairy Research 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)