Everything You Need to Know About Lateral Flow Tests for Coronavirus
Coronaviruses are a large family of viruses, which includes the virus that causes the common cold, as well as the virus responsible for SARS (severe acute respiratory syndrome). With so many members, it may seem like they’re all similar, but this couldn’t be further from the truth. Each has its own unique genetic makeup, so that no two coronaviruses look or act exactly alike. While some cause only mild symptoms in their hosts, others can be deadly—and so identifying them is essential to both public health and patient care. That’s where lateral flow tests come in!
What are Lateral Flow Tests?
A lateral flow test is a rapid immunochromatographic assay designed to detect specific proteins in human body fluids. For example, a lateral flow test might be used by doctors or patients to detect antibodies against influenza virus (the flu). The antigen in a lateral flow test is often protein-based, but can also be synthetic DNA, RNA, or small molecules that are chemically synthesized. Although these components aren’t alive like bacteria and viruses, we still call them antigens because they produce antibodies when introduced into human body fluids such as blood and saliva. The antibodies produced by humans during a reaction with an antigen are known as immunoglobulins or just Igs for short. There are five different types of Ig: IgA, IgD, IgE, IgG, and IgM. We use our immune system to fight off infections from foreign substances entering our bodies. This includes infectious agents like bacteria and viruses. In order for our immune system to work properly it needs two things: 1) receptors on cells that recognize harmful substances entering our bodies; 2) antibodies which will neutralize those harmful substances so they cannot cause harm anymore. Antibodies bind specifically to their corresponding antigens which allows them to neutralize their target pathogen before it can cause harm within our bodies.
Component Parts
The term lateral flow device is a catch-all phrase describing any type of diagnostic test that uses a strip or strip-like sample holder. Strips are made from porous paper, and their structure allows small samples of bodily fluids—for example, urine or blood—to be transported up and through them. The transportation process occurs via capillary action (think diffusion) because a substance naturally moves from areas of high concentration toward areas of low concentration. In lateral flow devices, strips undergo some sort of color change as they take in small amounts of sample liquid; once that happens, detection is simple: all you have to do is look at what was originally white and see if it has changed color anywhere along its length. If it has, then there’s a good chance you’re dealing with something that could cause illness.
Testing Solutions
Before mass testing can commence, a quality-assurance strategy must be created and implemented. When constructing such a plan, it is critical that test providers make sure they use quality materials that will enable easy traceability between samples and their respective results (DOI:10.15171/ijhc). It's also important to make sure samples are tested quickly after collection so pathogens do not have an opportunity to mutate or grow. This is where test strip lateral flow tests (LFTs) come in handy. These strips self-isolate themselves from additional biological materials on their surface and provide an end-to-end solution at scale by allowing providers to immediately begin testing samples in bulk without spending time prepping test panels (Figure 1). Once samples are collected, all you need to do is immerse them into a sample buffer provided with each LFT kit and place them into a reader. The reader then automatically detects which pathogen has been detected based on changes in color of each test pad. If you're looking for traceability and ease of use, we recommend using one of our covid-19 lateral flow tests as part of your QA strategy if you have covid-19 symptoms.
What to Consider When Choosing a Test Kit
When determining what test kit is best for you, consider ease of use and convenience. It's also important to make sure that you can trust your test results, so look at how well each kit is designed. A good indicator of quality is whether or not an antigen test kit has been approved by a regulatory body such as Australia's Therapeutic Goods Administration (TGA). This means that it has been tested and proven safe and effective before being put on sale in Australia. The same applies in Europe, where a CE mark indicates that a product meets European safety standards. If a product has both of these certifications, it can be trusted. How Do Lateral Flow Tests Work? When used correctly, lateral flow tests are extremely accurate. How do they work? Each test starts with an absorbent pad called a nitrocellulose membrane (NCM) placed onto a plastic card or tray which contains areas for controls and samples. An area containing antigens is located at one end of the NCM membrane; another contains antibodies specific to those antigens. Antibodies are proteins produced by immune cells which identify foreign substances in our bodies – they're like our own personal CSI team.
How Do They Work?
Lateral flow tests (LFTs) also called LFDs are a form of immunoassay. They measure antibody or antigen levels in your sample, like blood, nasal swabs, urine, etc. Unlike ELISA tests that rely on liquid chromatography and mass spectrometry (HPLC/MS), you can use them without any kind of equipment or training. Instead, they use a chemical dye which is drawn along a line in proportion to your level of marker in your sample. They’re often used by doctors and public health workers during outbreaks like SARS-CoV and Swine Flu; it only takes about 20 minutes for results to show up. In fact, there’s an entire field called rapid diagnostics dedicated to developing these kinds of tests.
You might be wondering how these little strips on rapid lateral flow tests know what color to turn when your sample hits them, like a pregnancy test. That happens thanks to something called lateral flow technology: basically, it's a test strip with three different layers stacked one on top of another. The first layer has antibodies attached; as your sample flows through, it binds with those antibodies if there's anything in there that matches what's written on the strip—in other words, if you have coronavirus antibodies in your body. If so, it will bind those antibodies and carry them into the second layer where they'll bind with some more stuff that's attached there.
How Do I Use Them?
Using a lateral flow test is actually quite simple. To begin, collect an appropriate amount of saliva, nasal discharge, or other bodily fluid and place it in a disposable collection device. Next, place a sample on one side of your chosen test strip (usually an at-home test will come with multiple strips). When you’re ready to read results, simply follow instructions printed on the strip. This can include either placing your hand into a cup of buffer solution or immersing your strip in liquid (or both). For example, most pandemic flu tests require that you immerse a strip in buffer solution containing iodide ions; if your sample contains SARS-CoV antigens and antibodies, they’ll bind and change color after about 15 minutes. The final step is to compare your results against a chart included with your kit. If you see two pink lines, you may have contracted SARS-CoV.
How Long Will My Test Last?
The viability of any test will vary based on how it’s used and what type of sample is being tested. Most lateral flow tests, especially those that are intended for use by first responders and health care workers in high-risk areas, can last anywhere from five minutes to five hours—and in some cases, up to 10 hours. It depends on a few factors, including how many steps you’re taking during each process. In addition, each test has its own expiration date; make sure you know exactly when your particular kit expires so you don’t get a false-positive result or a false negative result on a negative test because it expired. A false positive could mean unnecessary treatment and a missed opportunity to treat an actual case of disease, while a false negative could mean missing out on treatment altogether. If you have multiple kits available, rotate them every two hours (or as often as necessary) so they don’t expire before they’ve been put to good use. And if you aren't using all your kits within their recommended lifespan, store them properly in accordance with package instructions to extend their shelf life. For example, if you need to keep one set at room temperature but another set at refrigerated temperatures, follow manufacturer instructions carefully.
Final Thoughts on LFTs
LFTs or lateral flow tests are a relatively new test format in comparison to ELISA, and they can be used in many areas of social care, including childcare. The SARS-Cov-2 antigen has been around since 2003, but is only starting to be integrated into healthcare facilities. Instead of using traditional dipsticks or lateral flow assays, manufacturers may have something that is more traceable and more easily obtained. This will reduce time between testing and making an informed decision about patients. Both private and public facilities need appropriate safeguards regarding healthcare supplies as well as for public health. Therefore it's important to note there are varying risk factors that each facility should keep in mind when deciding on which product best suits their needs. In addition, we've learned that some products might not work well with certain sample types. For example, Covid-19 was shown to not perform as expected with urine samples from men who had recently smoked marijuana (3). While these were two different products being tested on two different samples types, you'll want to make sure your products aren't affected by things like these before you begin using them. As we move forward with additional research and development in regards to disease diagnostics we'll continue to see these devices become even more reliable and cost effective.
