title: Dual-signal analysis eliminates requirement for milk sample pretreatment.
abstract: Detection of analytes in complex biological samples, such as milk and blood, normally requires sample pretreatment. These pretreatment regimes reduce assay throughput and increase testing costs. Technologies that make it possible to eliminate sample pretreatment are of great industrial interest. Here we report the development of a dual-signal flow injected analysis device which eliminates the need for sample pretreatment. The device employs thermal traducers to measure the signal from an enzyme and a reference column. This makes it possible to independently monitor and correct for non-specifically generated heat, thereby eliminating the need for sample pretreatment. The ability of the dual-signal device to determine urea and lactate in milk samples without any prior treatment was evaluated. The spiked milk samples, the urea assay had a linear range from 0.1 to 50mM (R=0.996), and the lactate assay had a linear range from 0.025 to 5.0mM (R=0.9998). The linear regression values for urea and lactate for 0.5%, 1.5% and 3.0% fat milk were at least 0.990. The dual-signal design improves assay reproducibility, accuracy and sensitivity. Addition benefits are shorter assay times and lowers costs, as well as reducing equipment and training requirements. The potential application of the technology for multi-analyte analysis in point of care and decentralized diagnostic testing in healthcare, agriculture and environmental areas is discussed.
authors.affiliation: Institute of Environmental Medicine, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, PR China. Ying.Chen@tbiokem.lth.se
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Anneli
authors.initials: A
authors.lastname: Andersson
authors.forename: Michael
authors.initials: M
authors.lastname: Mecklenburg
authors.forename: Bin
authors.initials: B
authors.lastname: Xie
authors.forename: Yikai
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D002374:Catalase; D004800:Enzymes, Immobilized; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D019344:Lactic Acid / Q000032:analysis; D008892:Milk / Q000737:chemistry*; D006899:Mixed Function Oxygenases; D014508:Urea / Q000032:analysis; D014510:Urease
chemical_list: D004800:Enzymes, Immobilized; D019344:Lactic Acid; D014508:Urea; D006899:Mixed Function Oxygenases; D002374:Catalase; C021497:lactate 2-monooxygenase; D014510:Urease