Diazyme DZ-Lite SARS CoV-2 IgM and IgG CLIA Kits Frequently Asked Questions (FAQs)
- About Diazyme Laboratories, Inc.
- What is SARS-CoV-2 and What is COVID-19?
- What is the Incubation Period for COVID-19?
- What are the Guidelines on Testing People for COVID-19?
- What is IgM and What is IgG?
- What are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- How Are the Diazyme Kits Useful?
- How Are the Diazyme Kits Different from RT-qPCR?
- How Do the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Work?
- Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Microplate-Based?
- Do I need a Special Analyzer to Run the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- What are the Dimensions of the Diazyme DZ-Lite 3000 Plus Analyzer?
- Does the Diazyme DZ-Lite 3000 Plus Analyzer Need Special Water/Waste Hookups?
- What is the Throughput of the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- How Many Tests are there in the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- What Type of Samples Can I Use with the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- How do I Ship Specimen to Be Tested with the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- What are the Storage Conditions and Stability Profiles for the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- What is the Cut-Off for Reporting Results?
- Can I Test Pooled Samples?
- What are the Interference and Cross-reaction Profiles of the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- Do the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Include Calibrators and Controls?
- How Sensitive Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- How Specific Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits
- What are the Cross-reactivity Profiles of the Diazyme SARS-CoV-2 IgM and IgG CLIA Kits?
- Which SARS-CoV-2 Antigen is Used in the Diazyme IgM/IgG CLIA Kits?
- Regulatory Statements
- About Diazyme Laboratories, Inc.
Diazyme Laboratories, Inc. (Diazyme) is a cGMP and ISO 13485 certified medical device manufacturer located in Poway, California. The company is an affiliate of San Diego-based General Atomics and has been in business for 20 years. With subsidiaries in Germany and in China and over 150 employees, Diazyme develops user-friendly and high-throughput diagnostic reagents which can be used on automated chemistry analyzers. Diazyme's line of products include test kits for diagnosis of cardiovascular disease, liver disease, cancer markers, renal disease, diabetes, electrolytes and infectious diseases.
- What is SARS-CoV-2 and What is COVID-19?
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the official name of the novel coronavirus that is currently causing a worldwide pandemic. COVID-19 is the official name of the respiratory disease caused by SARS-CoV-2. SARS-CoV-2 is highly contagious and is transmitted through respiratory droplets and contact with contaminated surfaces. More information about COVID-19 can be found at the Center for Disease Control and Prevention CDC website: https://www.cdc.gov/coronavirus/2019-nCoV/index.html as well as on https://www.coronavirus.gov/
- What is the Incubation Period for COVID-19?
Although several studies are still in progress, according to the March 10th, 2020 study published in the Annals of Internal Medicine, the incubation period for COVID-19 as measured from publicly confirmed cases is as follows1:
- Median Incubation period: 5.1 days (95% confidence interval, 4.5 to 5.8 days)
- 97.5 % of those who develop symptoms will do so within 11.5 days (CI, 8.2 to 15.6 days)
- Under conservative estimates, 101 cases out of 10,000 cases (99th percentile, 482) will develop symptoms after 14 days of active monitoring or quarantine.
1Lauer SA, Grantz KH, Bi Q, Jones FK, Zheng Q, Meredith HR, Azman AS, Reich NG, Lessler J. The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application. Ann Intern Med. 2020 Mar 10.
- What are the Guidelines on Testing People for COVID-19?
The CDC is continuously updating this information at: https://emergency.cdc.gov/han/2020/han00429.asp
As of March 08, 2020, the CDC stated that “Clinicians should use their judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested”. In addition, priority testing should be given to:
- Hospitalized patients who have signs and symptoms compatible with COVID-19 in order to inform decisions related to infection control.
- Other symptomatic individuals such as, older adults (age ≥ 65 years) and individuals with chronic medical conditions and/or an immunocompromised state that may put them at higher risk for poor outcomes (e.g., diabetes, heart disease, receiving immunosuppressive medications, chronic lung disease, chronic kidney disease).
- Any persons including healthcare personnel, who within 14 days of symptom onset had close contact with a suspect or laboratory-confirmed COVID-19
patient, or who have a history of travel from affected geographic areas within 14 days of their symptom onset.
- What is an IgM and What is an IgG?
Upon infection with the SARS-CoV-2 virus, the patient’s immune system tries to fight the virus by producing blood-circulating molecules known as antibodies. IgM is a class of antibodies that appears early after an infection (as early as 3-5 days). IgM is the body’s first line of defense against a foreign antigen. IgG is another class of antibodies that appears later and gradually replaces the IgM antibodies. Usually, IgG antibodies appear in the blood circulation within 3-4 weeks after initial infection. The presence of SARS-CoV-2-specific IgM and/or IgG antibodies in the blood of a patient is a strong indication that the patient has been infected with the SARS-CoV-2 virus.
- What are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- The Diazyme DZ-Lite SARS-CoV-2 IgM CLIA kit a set of reagents that specifically detects the presence/absence of COVID-19-specific IgM antibodies in the blood of a patient.
- The Diazyme DZ-Lite SARS-CoV-2 IgG CLIA kit a set of reagents that specifically detects the presence/absence of COVID-19-specific IgG antibodies in the blood of a patient.
- How Are the Diazyme Kits Useful?
- The product is intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection. At this time, it is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity.
- Serological tests are important to understand true community spread of the COVID-19 disease as studies imply a certain percentage of the population may not be symptomatic. Proper use of serological tests allows Public Health Officials to better understand infection rate, true mortality rate and understand the risk of disease reemergence as stricter lockdown and distancing measures are eased.
- Diazyme CLIA serological tests have less pre-analytical requirements and do not involve complex extraction procedures.
- How Are the Diazyme Kits Different from RT-qPCR?
Nucleic Acid Amplification Tests (NAAT) detects the presence of the virus SARS-Cov-2 that caused the respiratory disease COVID-19. The current nucleic acid test for SARS-CoV-2 is based on the detection of the virus’ ribonucleic acid (RNA) using a modified version of the polymerase chain reaction technique (RT-qPCR). Although the technique itself is sensitive, the test has several limitations that include:
- Low throughput: First results take up to 3.5 hours.
- High complexity: Several manual steps are required by highly trained personnel
- Variability in accuracy: The test may not detect patients who have been infected but have low viral load during swabbing.
- The swabbing, transport and extraction steps may be subject to error.
The SARS-CoV-2 IgM CLIA and SARS-CoV-2 IgG CLIA tests do not detect SARS-Cov-2 virus. The serology (antibody) tests detect the immune response to SARS-CoV-2 infection. Features include:
- Routine blood draws
- Higher throughput: First results appear after 34 min, which makes large scale testing of whole populations possible.
- Less complex process: The current IgM/IgG tests are fully automated and the operator is only in charge of placing samples and ordering tests on a computer interface.
- How Do the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Work?
- The Diazyme SARS-CoV-2 IgM CLIA kit is a capture chemiluminescence immunoassay. Using a fully automated chemiluminescence analyzer, the blood sample of a patient goes through a series of treatments with various reagents to generate a light signal that is proportional to the concentration of SARS-CoV-2 IgM antibodies.
- The Diazyme SARS-CoV-2 IgG CLIA kit is an indirect chemiluminescence immunoassay. Using a fully automated chemiluminescence analyzer, the blood sample of a patient goes through a series of treatments with various reagents to generate a light signal that is proportional to the concentration of SARS-CoV-2 IgG antibodies.
- Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Microplate-Based?
No, the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA tests do not use microplates and are not ELISA assays. Samples are loaded in batch on the chemiluminescence analyzer in a manner similar to that of a general chemistry analyzer.
- Do I need a Special Analyzer to Run the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Yes, the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA tests are closed barcoded systems that run only on the Diazyme DZ-Lite 3000 Plus chemiluminescence analyzer, which is provided by Diazyme to prospective clinical labs. The Diazyme DZ-Lite 3000 Plus chemiluminescence analyzer is an FDA 510k cleared instrument for clinical diagnostic uses.
- What are the Dimensions of the Diazyme DZ-Lite 3000 Plus Analyzer?
- Depth: 30 in
- Height: 60 in (78 in when open)
- Width: 63.5in
Please contact our Technical Support at support@diazyme.com for analyzer installation requirements.
- Does the Diazyme DZ-Lite 3000 Plus Chemiluminescence Analyzer Need Special Water/Waste Hookups?
No, the Diazyme DZ-Lite 3000 Plus chemiluminescence analyzer is a self-contained water/waste system and does not need to be connected to lab water/waste hookups.
Please contact our Technical Support at support@diazyme.com for analyzer installation requirements.
- What is the Throughput of the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
When running both the IgM and IgG tests in parallel, the throughput on the Diazyme DZ-Lite 3000 Plus chemiluminescence analyzer is estimated at ~ 50 tests/hour. If 100% of instrument test capacity is dedicated to the test, then reagents for 2500 tests can be loaded at one time.
- How Many Tests are there in the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Both the DiazymeDZ-Lite SARS-CoV-2 IgM and IgG CLIA kits contain 100 tests each.
- What Type of Samples Can I Use with the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
- Serum and plasma (potassium EDTA, disodium EDTA and lithium heparin) samples can be used with the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG assays.
- Do not open the sample tube cap before finishing inactivation to prevent operators from being exposed.
- Inactivation: Blood samples need to be inactivated by heating the samples in a laboratory water bath of 56°C for 30 minutes before loading the samples on the analyzer.
Please refer to the CDC Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Coronavirus Disease 2019 (COVID-19): https://www.cdc.gov/coronavirus/2019-nCoV/lab/lab-biosafety-guidelines.html as well as your local, state and federal government’s mandated requirements.
- How do I Ship Specimen to Be Tested with the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits to Clinical Laboratories?
It is recommended to ship samples at 2-8°C using an overnight freight service. Alternatively, samples can be shipped frozen. Before shipping, it is recommended that specimens be removed from the separator, red blood cells or clot. Heat inactivation should be performed prior to removing from the separator, red blood cells or clot.
- What are the Storage Conditions and Stability Profiles for the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Store all kit components at 2-8°C.
- Unopened reagents are stable at 2-8°C until expiration date.
- Open reagent kits are stable at 2-8°C for 6 weeks.
- Onboard reagent kits are stable at 2-8°C for 4 weeks.
- What is the Cut-Off for Reporting Results?
The recommended Cut-Off for both the Diazyme IgM and IgG CLIA kits is 1.00 AU/mL: Results lower than 1.00 AU/mL are reported “< (Non-Reactive). Results higher than 1.00 AU/mL are reported “> (Reactive)
- Can I Test Pooled Samples?
No
- What are the Interference and Cross-reaction Profiles of the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Please refer to the package insert (IFU).
- Do the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits Include Calibrators and Controls?
Yes, the kits include two calibrators (one high and one low) and two controls: one
positive and one negative.
- How Sensitive Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Clinical sensitivity is defined as the ability to correctly identify those patients who were infected. Several studies have been performed with the SARS-CoV-2 IgM and IgG CLIA test Kits.
Positive Percent Agreement (PPA) = [IgG or IgM positive]/ [RT-PCR positive]
- SARS-CoV-2 IgG
Overall PPA >7 days post symptom onset: 96.2% for IgG
PPA ≥15 days post symptom onset: 100% for IgG - SARS-CoV-2 IgM
Overall PPA >7 days post symptom onset: 92.1% for IgM
PPA ≥15 days post symptom onset: 93.9% for IgM
- How Specific Are the Diazyme DZ-Lite SARS-CoV-2 IgM and IgG CLIA Kits?
Clinical specificity is defined as the ability to correctly identify those patients who were not infected. Several studies have been performed with the SARS-CoV-2 IgM and IgG CLIA test Kits.
- Using 852 presumptive negative specimens collected before December 2019, the clinical specificity of the Diazyme DZ-Lite SARS-CoV-2 IgG CLIA test was estimated at 97.4%.
- Using 302 presumptive negative specimens collected before December 2019, the clinical specificity of the Diazyme DZ-Lite SARS-CoV-2 IgM CLIA test was estimated at 98.3%
- What are the Cross-reactivity Profiles of the Diazyme SARS-CoV-2 IgM and IgG CLIA Kits?
The cross-reactivity of both Diazyme SARS-CoV-2 IgM and IgG CLIA kits to antibodies against various viruses (including four coronaviruses: HKU1, OC43, NL63, 229E) and bacteria has been tested. Results are shown below:
Cross-Reactant
Cross-Reactivity Result
Influenza A H1N1 IgM/IgG Negative Influenza A H1N1 seasonal IgM/IgG Negative Influenza A H3N2 IgM/IgG Negative Influenza A H5N1 IgM/IgG Negative Influenza A H7N9 IgM/IgG Negative Influenza B Yamagata IgM/IgG Negative Influenza B Victoria IgM/IgG Negative Respiratory syncytial virus IgM/IgG Negative Rhinovirus Type A IgM/IgG Negative Rhinovirus Type B IgM/IgG Negative Rhinovirus Type C IgM/IgG Negative Adenovirus Type 1 IgM/IgG Negative Adenovirus Type 2 IgM/IgG Negative Adenovirus Type 3 IgM/IgG Negative Adenovirus Type 4 IgM/IgG Negative Adenovirus Type 5 IgM/IgG Negative Adenovirus Type 7 IgM/IgG Negative Enterovirus Type A IgM/IgG Negative Enterovirus Type B IgM/IgG Negative Enterovirus Type C IgM/IgG Negative Enterovirus Type D IgM/IgG Negative EBV VCA IgM/IgG Negative EBV NA IgG Negative Measles virus IgM/IgG Negative Human Cytomegalovirus IgM/IgG Negative Rotavirus IgM/IgG Negative Norovirus IgM/IgG Negative Mumps virus IgM/IgG Negative Varicella-zoster virus IgM/IgG Negative Mycoplasma pneumoniae IgM/IgG Negative SARS-CoV-2 IgM Negative Human coronavirus HKU1 IgM/IgG Negative Human coronavirus OC43 IgM/IgG Negative Human coronavirus NL63 IgM/IgG Negative Human coronavirus 229E IgM/IgG Negative Parainluenza virus Negative Measles virus Negative Chlamydia pneumoniae IgM/IgG Negative Candida albicans Negative ANA Negative
Additionally, the Diazyme SARS-CoV-2 IgM CLIA kit did not cross-react with SARS-CoV-2 IgG antibodies and vice versa (the Diazyme SARS-CoV-2 IgG CLIA kit did not cross-react with SARS-CoV-2 IgM antibodies).
- Which SARS-CoV-2 Antigen is Used in the Diazyme IgM/IgG CLIA Kits?
For optimum specificity, the Diazyme SARS-CoV-2 IgM and IgG CLIA kits specifically use the N and S proteins of the virus as antigens for the IgM and IgG antibodies.
- Regulatory Statements
Diazyme DZ-Lite SARS-CoV-2 CLIA IgG kits (FDA EUA)
- This test has not been FDA cleared or approved;
- This test has been authorized by FDA under an EUA for use by authorized laboratories;
- This test has been authorized only for the presence of IgG antibodies against SARS-CoV-2, not for any other viruses or pathogens; and
- This test is only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of in vitro diagnostics for detection and/or diagnosis of COVID-19 under Section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner.
- This test is not for the screening of donated blood
Diazyme DZ-Lite SARS-CoV-2 CLIA IgM kits (Section IVD Notified. Under EUA review)
- This test has not been reviewed by the FDA.
- Negative results do not rule out SARS-CoV-2 infection, particularly in thosewho have been in contact with the virus. Follow-up testing with a moleculardiagnostic should be considered to rule out infection in these individuals.
- Results from antibody testing should not be used as the sole basis to diagnose orexclude SARS-CoV-2 infection or to inform infection status.
- This test is not for the screening of donated blood
FDA notifications are now listed on the FDA’s website under “FAQs on Diagnostic Testing for SARS-CoV-2”: https://www.fda.gov/medical-devices/emergency-situations-medical-devices/faqs-diagnostic-testing-sars-cov-2
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