Ultra-sensitive magnetic assays for sepsis diagnostics

描述（申请人提供）：该项目旨在将超灵敏磁性检测平台应用于脓毒症病原体的快速早期诊断。该技术平台基于用磁性纳米颗粒标记生物分子，并使用专利的超灵敏磁性传感器检测结合时产生的磁场。 虽然最初的重点将是直接检测两个主要的“原理证明”演示， 病原体，金黄色葡萄球菌和大肠杆菌，负责败血症，诊断平台 应该普遍适用于广泛的病原体。 活细菌的直接检测将通过测量磁性标记的 靶病原体表面抗原的抗体。购买的细菌将首先用于 在快速、“混合和测量”的磁性检测中证明了高灵敏度的概念验证。下一代原型仪器将被生产并放置在我们的合作者波士顿儿童医院。将检查现有IRB批准的记录有感染的临床标本库（600份血液和尿液样本，150份气管）抽吸物，以证明临床实用性，包括灵敏度、特异性和较短的检测时间。 该程序的最终目标是在临床样品中显示< 100个细菌/ml的检测限，总（制备和测量）测定时间小于15分钟。此外，在小样品中的检测限低至5-10个细菌（例如，20 μ l）可以通过使用磁场外部操纵磁性纳米颗粒标记的独特能力来实现。注意，磁性检测不受生物流体中的测量的阻碍，并且在微孔板威尔斯中的混合和测量形式需要很少的样品制备，从而最小化误差。

DESCRIPTION (provided by applicant): The program is aimed at applying an ultra-sensitive magnetic detection platform to the rapid and early diagnosis of pathogens causing sepsis. The technology platform is based on labeling biomolecules with magnetic nanoparticles and detecting the magnetic field generated upon binding using patented ultra-sensitive magnetic sensors. While the initial focus will be on a "proof-of-principle" demonstration for the direct detection of two major pathogens, Staphylococcus aureus and Escherichia coli, responsible for sepsis, the diagnostic platform should be generally applicable to a wide range of pathogens. Direct detection of live bacteria will be demonstrated by measuring the binding of magnetic labeled antibodies to a surface antigen on the target pathogen. Purchased bacteria will first be used to demonstrate a proof-of-concept for high sensitivity in a rapid, "mix and measure" magnetic assay. A next generation prototype instrument will then be produced and placed at our collaborator, Children's Hospital Boston. An existing IRB-approved library of clinical specimens with documented infections (600 blood and urine samples, 150 trachea) aspirates) will be examined in order to demonstrate clinical utility, including sensitivity, specificity and short assay times. The ultimate goal of this program is to show a limit of detection < 100 bacteria/ml in clinical samples with a total (preparation and measurement) assay time of less than 15 minutes. Additionally, detection limits as low as 5-10 bacteria in small samples (e.g., 20 ul) may be possible by using the unique ability to externally manipulate magnetic nanoparticle labels using magnetic fields. Note that magnetic detection is not hampered by measurement in biological fluids and the mix and measure format in microplate wells requires little sample preparation, thereby minimizing errors.