Quantigen Biosciences, Fishers, Indiana, United States of America.
The Everett Clinic-Part of Optum, Everett, Washington, United States of America.
PLoS One. 2021 Apr 14;16(4):e0245423. doi: 10.1371/journal.pone.0245423. eCollection 2021.
In order to identify an inexpensive yet highly stable SARS-CoV-2 collection device as an alternative to foam swabs stored in transport media, both contrived ("surrogate") CoV-positive and patient-collected spun polyester swabs stored in dry tubes were evaluated for time- and temperature-stability using qPCR.
Surrogate specimens were prepared by combining multiple, residual SARS-CoV-2-positive clinical specimens and diluting to near-LOD levels in either porcine or human mucus ("matrix"), inoculating foam or polyester nasal swabs, and sealing in dry tubes. Swabs were then subjected to one of three temperature excursions: (1) 4°C for up to 72 hours; (2) 40°C for 12 hours, followed by 32°C for up to 60 hours; or (3) multiple freeze-thaw cycles (-20°C). The stability of extracted SARS-CoV-2 RNA for each condition was evaluated by qPCR. Separate usability studies for the dry polyester swab-based HealthPulse@home COVID-19 Specimen Collection Kit were later conducted in both adult and pediatric populations.
Polyester swabs stored dry demonstrated equivalent performance to foam swabs for detection of low and moderate SARS-CoV-2 viral loads. Mimicking warm- and cold- climate shipment, surrogate specimens were stable following either 72 hours of a high-temperature excursion or two freeze-thaw cycles. In addition, usability studies comprised of self-collected patient specimens yielded sufficient material for molecular testing, as demonstrated by RNase P detection.
Polyester nasal swabs stored in dry collection tubes offer a robust and inexpensive self-collection method for SARS-CoV-2 viral load testing, as viral RNA remains stable under conditions required for home collection and shipment to the laboratory.
为了寻找一种廉价且高度稳定的 SARS-CoV-2 采集装置来替代储存在运输介质中的泡沫拭子，本研究评估了干管中保存的人工（“替代”）CoV 阳性和患者采集的聚酯纺丝拭子在时间和温度稳定性方面的性能，使用 qPCR 进行检测。
通过将多个残留的 SARS-CoV-2 阳性临床标本混合并稀释至接近 LOQ 水平，在猪或人黏液（“基质”）中制备替代标本，接种泡沫或聚酯鼻拭子，并密封在干管中。然后将拭子置于三种温度波动条件之一：（1）4°C 条件下，最长 72 小时；（2）40°C 条件下 12 小时，然后 32°C 条件下，最长 60 小时；或（3）多次冻融循环（-20°C）。通过 qPCR 评估每种条件下提取的 SARS-CoV-2 RNA 的稳定性。随后，在成人和儿科人群中分别对基于干聚酯拭子的 HealthPulse@home COVID-19 样本采集试剂盒进行了单独的可用性研究。
干燥保存的聚酯拭子在检测低和中度 SARS-CoV-2 病毒载量方面的性能与泡沫拭子相当。模拟温暖和寒冷气候的运输条件，替代标本在高温条件下 72 小时或两次冻融循环后均保持稳定。此外，由患者自行采集的标本进行的可用性研究产生了足够用于分子检测的材料，这一点通过 RNase P 检测得到了证实。
干燥收集管中保存的聚酯鼻拭子为 SARS-CoV-2 病毒载量检测提供了一种稳健且廉价的自我采集方法，因为病毒 RNA 在家庭采集和运输到实验室所需的条件下保持稳定。
