3 COVID-19 PCR 检测的关键步骤

PCR 测试一直是诊断 COVID-19 的金标准测试, 它准确可靠. COVID-19 PCR 检测的三个关键步骤:

• 样品采集: 医疗保健提供者使用棉签收集您鼻子中发现的呼吸道物质. 棉签是长长的柔软的尖端, 灵活的棍子进入你的鼻子. There are different types of nose swabs, including nasal swabs that collect a sample immediately inside your nostrils and nasopharyngeal swabs that go further into the nasal cavity for collection. Either type of swab is sufficient for collecting material for the COVID-19 PCR test. 收藏后, the swab is sealed in a tube and then sent to a laboratory.
• Extraction: When a laboratory scientist receives the sample, they isolate (extract) genetic material from the rest of the material in the sample.
• 聚合酶链反应: The PCR step then uses special chemicals and enzymes and a PCR machine called a thermal cycler. Each heating and cooling cycle increases (amplifies) the amount of the targeted genetic material in the test tube. After many cycles, 试管中存在数百万份 SARS-CoV-2 病毒的一小部分遗传物质. 如果样本中存在 SARS-CoV-2，管中的一种化学物质会产生荧光. 一旦放大到足够, PCR机器可以检测到这个信号. 科学家使用特殊软件将信号解释为阳性测试结果.