The NIDS COVID-19 antigen rapid test is a fast, antigen-based test designed specifically for the qualitative detection of SARS-Covid-2 virus. The test consists of a well-known Lateral Flow immunoassay system. Upon exposure to SARS-COV-2, the sample liquid, when added to the sample well, is transferred laterally over the test sample and into a separate well.
Thereafter, a sample is drawn by a needle from the well in which the sample has been moved to; this sample is then placed back into the Lateral Flow immunoassay system. A small amount of sample is then added to a second LFI immunoassay tube, which are then attached to a second machine, the V-Multi-Assay System, and then exposed to the antibody-coated sample.
In addition, the COVID-19 antigen rapid test can also be used for detecting SARS-CoV in other samples. An example of such samples includes semen samples or blood samples. When samples are prepared as described, they are subjected to a series of immunoassays and then placed into a second vial of LFI immunoassay system. This machine is capable of generating a large amount of antibody-coated lysates, and in turn, the samples can be tested for SARS virus by means of a COVID-19 antigen rapid test. The antigen-specific antigen-antibody reactions generated by the LFI immunoassay can also be used as a means of determining SARS virus titre in blood samples.
In addition, the COVID-19 antigen rapid test is also useful for the detection of other types of infectious agents in samples. Examples of sample materials that can be used in the COVID-19 antigen rapid test are urine samples, saliva samples, sweat samples and secretions, urine, blood and sputum samples, and urine or saliva swabs.
Before using the COVID-19 antigen rapid test, it is important that a thorough understanding of the method of testing must be established. The rapid test consists of a series of experiments in which a sample is added to a collection well and a portion of the sample is then placed in a second well. When a SARS-Covid-2 sample enters the first well, the sample is expected to bind to a SARS-Covid-2 antigen and migrate to another sample well.
The time to complete the tests varies with the type of test being used, and is dependent on the type of sample used. A number of tests are designed to improve the efficiency of the test, and these include: a post-test analysis that determine whether the SARS-Covid-2 sample is actually SARS-CoV infected, and whether there is any re-contamination of the sample from the second well or another well. A pre-test analysis is performed to determine whether there is a sufficient quantity of antibody-coated sample to allow the COVID-19 antigen rapid test to give a definitive answer.
During the test, the first sample in the collection well contains an antigenized sample that has been diluted with a laboratory-grade solution. and then allowed to remain in the second sample well for a time period of time. The time taken for the sample to diffuse is the antigen reaction time.
The COVID-19 antigen rapid test is ideal for identifying the SARS virus infection in saliva or urine samples. It is also useful for detecting other infectious agents, such as hepatitis B or E, cholera, diarrhea, salmonella, hepatitis A and hepatitis B virus (HBV) in urine or saliva samples. However, the test cannot be used to identify or rule out the presence of the causative agent. In addition, the test cannot be used to confirm SARS diagnosis.
The COVID-19 antigen rapid test has a positive predictive value of 95% when used to determine SARS-CoV infection in saliva but has a low sensitivity of only 55% when used to identify SARS-CoV infection in urine or saliva samples. This is due to the fact that the primary analyte, SARS-CoV, is not detectable in blood, cerebrospinal fluid, tissue culture or urine.
The sample may be tested in two ways: by placing the sample into a sample collection container that contains an antibody mixture and adding an anti-SARS-CoV antibody to the sample or by inserting a needle into a specimen bag and then incubating the sample in a laboratory centrifuge for two minutes. The latter method will allow the sample to become contaminated with antibody. and this contamination may lead to inaccurate results.
The results are then compared to the known co-reactions of the sample. If a match is found, the sample is considered to be SARS-CoV positive.