– PCR vs. Rapid Antigen vs. Antibody

PCR, rapid antigen, and antibody testing are the dominant methods global healthcare systems use to test citizens for Covid-19. Both tests use different kinds of samples and technologies to search for different hallmarks of the SARS-CoV-2 virus.


In the fight against COVID-19, having multiple tests for different settings and stages of a person's infection is key, from high-complexity laboratory capabilities (RT-PCR) to fast solutions that give results on the spot (Rapid antigen and rapid antibody solutions). From tests that detect the active virus to tests that detect antibodies in people who were previously infected. Rapid Covid Labs provides the most advanced FDA authorized tests available in the market, at the most competitive prices and with white-glove service.

What is RT-PCR Covid-19 Testing? “The Covid Test”
The Diagnostic Gold Standard


  • RT-PCR testing is the preferred Covid-19 diagnostic test used by hospitals and healthcare systems worldwide to detect the Covid-19 virus in the human body (and the only test accepted for travel). The test is used to detect antigens which exist prior to the body’s production of antibodies as an active immune response. By detecting viral RNA, which will be present even before symptoms of the disease are present, the tests can tell early-on whether or not you have the Covid-19 active virus.While many labs are severely backed up and results cannot be delivered for 3 – 15 days, we offer “white glove service” with SAME DAY to 2 day results. This is a very labor and technology laden test which can only be conducted by high complexity laboratories. Considered the “end-all” conclusive test for Covid-19 worldwide.

What is Rapid Covid-19 Testing? “The Rapid Test”
Used by Government Agencies


  • Rapid Covid Labs has collaborated with Abbott Laboratories to provide our patients a molecular point-of-care system which is administered for the detection of Covid-19. This advanced technology facilitates qualitative detection of the nucleic acid of SARS-CoV-2 virus in Covid-19 suspected patients. This technology is also known as Rapid Antigen Testing. This test is an automated assay that delivers results in just minutes, using a molecular platform. The molecular platform of the test is an instrument-based, isothermal system for rapid qualitative identification of the existence of a Covid-19 infectious disease. Its isothermal nucleic acid amplification technology facilitates accurate test results in less than one hour. The test detects nucleic acids from the RNA of the SARS-CoV-2 virus. Tests require a comfortable saliva, nasal or throat swab. Rapid Covid Labs provides SAME DAY RESULTS with this system. These test results are highly accurate and used by United States government agencies, first responders and corporations. That said, the testing is not yet accepted for travel.

What is Rapid Antibody Testing? “Serological Testing” Detection of prior infection


  • When a person is infected with the Covid-19 virus for the first time, the immune system triggers the production of antibodies that are specific to the Covid-19 virus. These antibodies have the power to attach to the virus so that the immune system can destroy it. It usually takes the body anywhere from 5 – 15 days from Covid-19 infection to produce antibodies. Antibody tests can detect current Covid-19 infection, but are primarily used to tell us who has already been infected. Antibodies may not show up until the illness has run its course. IgM antibodies are the first to appear followed by “immunity antibodies” designated as IgG. PCR, Antigen and Antibody tests complement each other to identify COVID-19 infected individuals, either symptomatic or asymptomatic.

Frequently Asked Questions

Where can I get tested?

We currently have testing centers in Los Angeles, Orange County and San Bernardino County. Centers are opening soon in Riverside County and San Diego.

How long will my appointment take?

Average time to take a sample is between 15 - 30 minutes

Which is the most sensitive, specific, and accurate test over-all?

RT-PCR is considered globally to be the most sensitive, specific and accurate test to diagnose an acute Covid-19 infection.

I have been exposed to someone who was diagnosed with Covid-19 and/or have symptoms, what test should I take?

Either RT-PCR or our Rapid Antigen Test is appropriate. RT-PCR has a higher sensitivity and specificity (is considered more accurate) than the rapid test, but results take longer and the cost is higher. Both are quite accurate in their diagnosis.

The airline, state, or country I am visiting requires proof and documentation that I am Covid-19 negative. Which test is the only test approved for travel?

T-PCR is currently the only test approved by airlines, states and countries.

Can you test me and provide written certified results within 72 hours of my departure?

Yes, Rapid Covid Labs can provide testing and results within the 72 hour required timeframe. Make sure you make an appointment in advance and state that the test is required for travel.

Do you accept insurance?

Rapid Covid Labs will provide a receipt along with your test results which will have the necessary information needed for you to request reimbursement from your insurance company. We do not bill insurance.

How does real time RT–PCR work with the COVID-19 virus?

A sample is collected from the parts of the body where the COVID-19 virus gathers, such as a person’s nose or throat. The sample is treated with several chemical solutions that remove substances such as proteins and fats and that extract only the RNA present in the sample. This extracted RNA is a mix of the person’s own genetic material and, if present, the virus’s RNA.

The RNA is reverse transcribed to DNA using a specific enzyme. Scientists then add additional short fragments of DNA that are complementary to specific parts of the transcribed viral DNA. If the virus is present in a sample, these fragments attach themselves to target sections of the viral DNA. Some of the added genetic fragments are used for building DNA strands during amplification, while the others are used for building the DNA and adding marker labels to the strands, which are then used to detect the virus.

The mixture is then placed in an RT–PCR machine. The machine cycles through temperatures that heat and cool the mixture to trigger specific chemical reactions that create new, identical copies of the target sections of viral DNA. The cycle is repeated over and over to continue copying the target sections of viral DNA. Each cycle doubles the previous number: two copies become four, four copies become eight, and so on. A standard real time RT–PCR set-up usually goes through 35 cycles, which means that, by the end of the process, around 35 billion new copies of the sections of viral DNA are created from each strand of the virus present in the sample.

As new copies of the viral DNA sections are built, the marker labels attach to the DNA strands and then release a fluorescent dye, which is measured by the machine’s computer and presented in real time on the screen. The computer tracks the amount of fluorescence in the sample after each cycle. When a certain level of fluorescence is surpassed, this confirms that the virus is present. Scientists also monitor how many cycles it takes to reach this level in order to estimate the severity of the infection: the fewer the cycles, the more severe the viral infection is.

How does Rapid Antigen testing work with the Covid-19 virus?

The Rapid Antigen assay performed on the ID NOW Instrument is a rapid molecular in vitro diagnostic test utilizing an isothermal nucleic acid amplification technology intended for the qualitative detection of nucleic acid from the SARS-CoV-2 viral RNA in direct saliva, nasal, nasopharyngeal or throat swabs from individuals who are suspected of COVID-19.

How does your Rapid Covid-19 antigen test compare to the “gold standard” RT-PCR?

Interim analysis of two ongoing multi-site clinical studies — one among urgent care clinics and the other conducted with hospitalized and nursing home patients — show our COVID-19 rapid test demonstrating strong agreement to lab-based molecular polymerase chain reaction (PCR) instruments when the majority of people are tested in the first seven days post onset symptoms. The early results from the urgent care clinics showed ≥94.7% in positive agreement (sensitivity) and ≥98.6% negative agreement (specificity) when compared to two different lab-based PCR reference tests. These initial findings strongly suggest our instruments — which delivers rapid results in less than an hour — performs best when patients are tested earlier following their first symptoms.

How does Rapid ANTIBODY testing work with the Covid-19 virus?

The COVID-19 Rapid POC test is a lateral flow immunoassay. A lateral flow immunoassay is a way to qualitatively assess the presence of an analyte from a patient sample or specimen. In this case, the analytes being detected are IgG and IgM antibodies specific for SARS-CoV-2. The IgG/IgM test cassette is a qualitative membrane-based immunoassay for the detection of IgG and IgM antibodies to Covid-19 in whole blood, serum or plasma specimens. The principle of this test uses a rapid chromatographic immunoassay for qualitative detection of a human glycoprotein. This COVID-19 Rapid Point of Contact test consists of two components, an IgG and an IgM. In the IgG component, anti-human IgG coats the G test line region. In the IgM component, anti-human IgM coats the M test line region. During testing, the specimen reacts with SARS-CoV-2 antigen-coated gold nanoparticles (AuNP) in the conjugation pad of the test cassette. Any antibody in the patient sample that recognizes the MK201027 SARS-CoV-2 antigen binds to the Antigen-AuNP complex. The mixture then migrates laterally across the membrane by capillary action/lateral flow. As these human antibody/antigen/AuNP complexes move across the test lines, they are captured at the anti-human IgM 'M' Line, the anti- human IgG 'G' Line, or both, depending on the antibody contents of the specimen.The sample first reaches the anti-human IgM antibodies which coat the M line. If the specimen contains IgM antibodies to SARS-CoV-2, a coloured line will appear in the M test line region. Next, the sample reaches the anti-human IgG antibodies which coat the G line. If a specimen contains IgG antibodies to Sars-CoV-2, the conjugate-specimen complex reacts with anti-human IgG. A colored line appears in the G test line region as a result.

Can you test all of our employees and provide a Certification?

Yes. Rapid Covid Labs initiated operations testing entire workgroups for restaurants and corporations. We now also test Hollywood productions in California and other parts of the United States. We test school districts, churches, and other large organizations with 15 - 1,500+ employees.

Can you test my entire family for Covid-19 Antibodies?

Yes. Give us a call and we can schedule private testing for your family.

Will test results be reported to County Health Departments?

Yes. All test results are reported daily, as required by law.

I had some symptoms a week or more ago (months) but have no symptoms now. I Am curious to see if it was Covid-19 and if I may now have protective antibodies, which test should I take?

Our Healgen Scientific or Auto-bio Diagnostics tests will tell you if you have antibodies to Covid-19. These tests provide results for both IgG (past) and IgM (current) antibodies to Covid-19. One test but results for both at the same time. 10 minute results!

What do I do If I test positive for IgG antibodies?

A positive test for IgG antibodies means that you have already been infected with the virus and have built up antibodies to the disease.

What happens if I test positive for IgM antibodies?

We recommend that anyone that tests positive for IgM antibodies immediately self-isolate and confirm the antibody test with a molecular test via RT-PCR or Rapid Antigen test.

Does the existence of Covid-19 IgG antibodies mean I'm immune to Covid-19 now?

Much research is currently underway to answer this question. Many scientists believe the existence of Covid-19 antibodies does confer immunity to getting the disease again. The World Health Organization has agreed with scientists in this matter. That said, clinical trials are underway to provide definitive answers, which could take years.

Where are your Covid-19 antibody tests processed?

Rapid Covid Labs has its own CLIA certified laboratory in Los Angeles.

How accurate are antibody tests?

Our tests are some of the most accurate available on the market today. We use serological tests that are being administered by healthcare providers globally (including most European and other western countries). Antibody testing in general is sensitive to timing. After initial infection, IgM antibodies are the first to be produced. The body typically takes 1-3 days before it starts building levels of IgM antibodies to become detectable. The existence of IgM antibodies can help diagnose an “acute” or “active” infection. On the other hand, IgG antibodies are produced days later, typically between 5 – 10 days after infection before detectable levels are present. IgG antibodies are then detectable for months to years depending on the individual.

Is Rapid Covid Labs certified, permitted and operating under California state law?

Yes. Rapid Covid Labs is fully compliant and has all necessary permits to operate legally in all cities and counties in California. We currently have testing centers in (or are opening soon) Los Angeles, Orange County, Riverside County, San Bernardino County, and San Diego.