These tests are very accurate because even if there's only a tiny amount of virus present in a patient sample,

此檢測非常準確，因為即使患者樣本中只有少量病毒，

PCR — which stands for polymerase chain reaction — is able to take genetic material from the virus, target specific gene segments that only the virus has,

PCR（聚合酶鏈鎖反應驗技術）也能從病毒中獲取遺傳物質，鎖定該病毒的特定基因片段，

and make a very large number of copies of those segments so that they can be detected and measured.

並大量製作這些片段副本，以便檢測及測量。

Using this method, a PCR test can tell you if you have COVID-19 right now, but not if you've had it in the past.

利用技術，PCR 檢測能測出您現在是否感染 COVID-19，但不會顯示過去是否曾感染。

Although this type of test usually delivers results in four to six hours,

儘管 PCR 檢測通常能在四到六小時內得出結果，

it's worth noting that PCR testing is very complicated and costly, and not all healthcare facilities have the ability to perform it.

值得注意的是，此測試非常複雜且成本高昂，並非所有醫療機構都有能力執行。

Facilities that can't run this type of test may have to send patient samples to a reference laboratory and wait several days for the results.

無法進行 PCR 檢測的機構可能得將患者樣本送往受託實驗室，等待幾天才能得到結果。

On the other side of this spectrum, the FDA has also approved a few rapid PCR-based tests that give results in less than an hour.

另外，FDA 還批准了一些以 PCR 為基礎的快篩，可在不到一小時內得出結果。

At least initially, these rapid tests were reserved for triaging patients in hospitals and for testing healthcare workers.

最初，這些快篩是為醫院分診患者和醫護人員檢測而保留的。

Now that the production of these tests has ramped up further, rapid corona testing centers for the general public are starting to open in several states across the U.S.

現在，這些快篩試劑生產量增加，美國各州將會陸續開設提供一般民眾檢測的新冠快篩中心。