Institute of Biomaterials and Biomedical Engineering, Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada;
Innis College, and Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, Canada;
Clin Chem. 2015 Feb;61(2):420-9. doi: 10.1373/clinchem.2014.232181. Epub 2014 Dec 15.
Whereas disease surveillance for infectious diseases such as rubella is important, it is critical to identify pregnant women at risk of passing rubella to their offspring, which can be fatal and can result in congenital rubella syndrome (CRS). The traditional centralized model for diagnosing rubella is cost-prohibitive in resource-limited settings, representing a major obstacle to the prevention of CRS. As a step toward decentralized diagnostic systems, we developed a proof-of-concept digital microfluidic (DMF) diagnostic platform that possesses the flexibility and performance of automated immunoassay platforms used in central facilities, but with a form factor the size of a shoebox.
DMF immunoassays were developed with integrated sample preparation for the detection of rubella virus (RV) IgG and IgM. The performance (sensitivity and specificity) of the assays was evaluated with serum and plasma samples from a commercial antirubella mixed-titer performance panel.
The new platform performed the essential processing steps, including sample aliquoting for 4 parallel assays, sample dilution, and IgG blocking. Testing of performance panel samples yielded diagnostic sensitivity and specificity of 100% and 100% for both RV IgG and RV IgM. With 1.8 μL sample per assay, 4 parallel assays were performed in approximately 30 min with <10% mean CV.
This proof of concept establishes DMF-powered immunoassays as being potentially useful for the diagnosis of infectious disease.
虽然传染病（如风疹）的疾病监测很重要，但识别有将风疹传染给后代风险的孕妇至关重要，这可能是致命的，并可能导致先天性风疹综合征（CRS）。在资源有限的环境中，传统的集中式风疹诊断模型成本过高，这是预防 CRS 的主要障碍。作为向分散式诊断系统发展的一步，我们开发了一种概念验证数字微流控（DMF）诊断平台，该平台具有中央设施中使用的自动化免疫分析平台的灵活性和性能，但具有鞋盒大小的外形尺寸。
DMF 免疫测定法是为检测风疹病毒（RV）IgG 和 IgM 而开发的，具有集成的样品制备。我们使用商业抗风疹混合滴度性能面板的血清和血浆样本评估了测定法的性能（灵敏度和特异性）。
新平台执行了基本的处理步骤，包括 4 个平行测定的样品等分、样品稀释和 IgG 阻断。对性能面板样本的测试得出了 RV IgG 和 RV IgM 的诊断灵敏度和特异性均为 100%和 100%。每个测定使用 1.8 μL 样本，大约 30 分钟内可完成 4 个平行测定，平均 CV 小于 10%。
该概念验证确立了 DMF 驱动的免疫测定法在传染病诊断方面的潜在用途。
