Swab Sample Transfer for Point-Of-Care Diagnostics: Characterization of Swab Types and Manual Agitation Methods
Swab Sample Transfer for Point-Of-Care Diagnostics: Characterization of Swab Types and Manual Agitation Methods
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DOI：
10.1371/journal.pone.0105786
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发表时间：
2014-09-02
期刊：
影响因子：
3.7
通讯作者：
Lutz, Barry R.
中科院分区：
文献类型：
--
作者：
Panpradist, Nuttada;Toley, Bhushan J.;Lutz, Barry R.
背景：全球对疾病检测和控制的需求加大了设计简单、可靠、负担得起和无仪器的即时检测（POC）的努力。在许多POC测试中，样品收集包括擦拭部位（如鼻子、皮肤），在液体中搅拌拭子以释放样品，并将液体转移到设备中进行分析。样品转移性能差会降低灵敏度和重现性。方法：在本研究中，我们比较了7种类型的棉签使用POC设备典型的手动搅拌方法的细菌释放效率。使用定量PCR （qPCR）对金黄色葡萄球菌在代表一系列采样场景的条件下的转移效率进行了测量：1)将小体积样品刺入拭子上，2)将拭子浸入过量样品中，以及3)从表面擦拭干燥样品。结果：对于大多数拭子（基于尖端流体容量），过量样品给出了预期的回收率；聚氨酯棉签显示出更高的回收率，表明在采样过程中有能力积累生物体。对于所有测试的拭子，干燥样品的回收率约为20-30%，这表明当生物应用于拭子的外表面时，拭子的结构和体积不那么重要。小体积样品导致最广泛的棉签类型之间的转移效率。人造丝拭子（63 μ L容量）对大容量样品表现良好，但对小容量样品的回收率较差。尼龙（100亩L）和聚酯拭子（27亩L）对小体积和大体积样品的回收率为中等。聚氨酯拭子（16 μ L）对所有样品类型均表现出良好的回收率。这项工作表明，拭子传递效率会受到拭子材料、结构、流体容量和样品细节的影响。本研究的结果和定量分析方法将有助于POC检测开发人员选择合适的拭子类型和转移方法。
Background: The global need for disease detection and control has increased effort to engineer point-of-care (POC) tests that are simple, robust, affordable, and non-instrumented. In many POC tests, sample collection involves swabbing the site (e.g., nose, skin), agitating the swab in a fluid to release the sample, and transferring the fluid to a device for analysis. Poor performance in sample transfer can reduce sensitivity and reproducibility.Methods: In this study, we compared bacterial release efficiency of seven swab types using manual-agitation methods typical of POC devices. Transfer efficiency was measured using quantitative PCR (qPCR) for Staphylococcus aureus under conditions representing a range of sampling scenarios: 1) spiking low-volume samples onto the swab, 2) submerging the swab in excess-volume samples, and 3) swabbing dried sample from a surface.Results: Excess-volume samples gave the expected recovery for most swabs (based on tip fluid capacity); a polyurethane swab showed enhanced recovery, suggesting an ability to accumulate organisms during sampling. Dry samples led to recovery of similar to 20-30% for all swabs tested, suggesting that swab structure and volume is less important when organisms are applied to the outer swab surface. Low-volume samples led to the widest range of transfer efficiencies between swab types. Rayon swabs (63 mu L capacity) performed well for excess-volume samples, but showed poor recovery for low-volume samples. Nylon (100 mu L) and polyester swabs (27 mu L) showed intermediate recovery for low-volume and excess-volume samples. Polyurethane swabs (16 mu L) showed excellent recovery for all sample types. This work demonstrates that swab transfer efficiency can be affected by swab material, structure, and fluid capacity and details of the sample. Results and quantitative analysis methods from this study will assist POC assay developers in selecting appropriate swab types and transfer methods.