So many tests, so many little lines.
Updated: Sep. 25, 2023 Originally Published: March 28, 2022Covid testing and vaccination has come a long way since 2020. Back at the start of the pandemic, tests were unreliable and nearly impossible to get. But now we have access to at-home Covid tests, sometimes even free ones from the government or your insurance provider, which is incredibly useful especially now that Covid cases across the country have been on the rise since the end of summer. They are convenient to have on hand if you’ve recently been exposed to someone with Covid, have symptoms that you suspect are Covid, or are going to visit someone elderly or vulnerable. In order to accurately read your test, it’s helpful to have pictures of positive Covid tests to use as a point of reference because the result is sometimes not glaringly obvious.
It’s fair to wonder whether or not at-home Covid tests are reliable. “Yes [at-home Covid tests are reliable], but as with all testing platforms they have advantages/disadvantages,” says Thomas Denny, a Professor in Medicine at the Duke Human Vaccine Institute at Duke University School of Medicine.
False negatives (you have Covid, but it’s not showing up on the test) are far more common than false positives (you don’t have Covid but the test indicates that you do). The best way to ensure that a negative result is correct is to keep testing, Denny says. “[False negatives] can be countered by repeat testing over a few days,” he explains, “Repeated negatives increase the certainty of a true negative.”
The FDA has extended the expiration date for many brands’ tests. You can look up your Covid test’s updated expiration date here.
There are two types of Covid-19 diagnostic tests that are FDA-approved for home testing: Rapid antigen tests, which most of the at-home tests are, and molecular tests commonly referred to as PCR (polymerase chain reaction) tests. Rapid antigen tests detect Covid when you're carrying a lot of the virus. Molecular tests tend to be more sensitive, so they can detect Covid infection earlier than antigen tests can — from a few hours up to a few days faster. However, that accuracy and speed come with a price tag, and the cheaper antigen tests are still an incredibly useful tool for detecting contagious Covid infection. It’s worth noting that Covid self-tests performed at home are not as reliable as those performed in a laboratory setting. However, if you have a positive result on either a rapid antigen or molecular test, you should trust that result, because false positives are very, very rare, says Denny.
“One of the biggest variables to all testing is to have a good quality swab process,” says Denny. It’s extremely important to read and follow the directions that come in your at-home Covid test so that you get an accurate result. As for when to take an at-home Covid test, there is no perfect answer. “When an individual turns positive is related to the specific variant, because they have different incubation periods, and how much exposure someone has had,” Denny explains.
Your best bet is to take a test as soon as you start experiencing symptoms, or once you know you’ve been exposed. If it comes back as a false negative at that point, Denny says you’re “most likely not able to transmit [the virus] to others on that day.” However, don’t trust the negative result right away, wait another day and take another test (and possibly a thir test another a day or so after that one).
If you have Covid-19 symptoms but your at-home test yields a negative result, the FDA advises testing again after 48 hours (2 days) until you’ve taken 3 tests. If you are still testing negative but have Covid symptoms, it might be time to visit a facility (like an urgent care) where you can get a laboratory PCR test.
If you test positive, the CDC recommends isolating for a minimum of 5 days, regardless of symptoms, and until you are fever-free for 24 hours and symptoms are generally improving. You should wear a mask for at least 10 days. Your immunity should last about 3 months. If you haven’t received the vaccine or booster yet, the latest shot, which rolled out in September 2023, offers protection from a variety of strains including the original Covid-19 strains and the most recently discovered ones.
So, how will you know if the test is positive, though? Here are some photos of positive Covid test results to help you read your result.
The BinaxNow Covid-19 Antigen Self-Test comes with a swab and a testing solution. Unlike a lot of other at-home Covid tests, this one has a fold-over card that’s used for testing. After swabbing the nose, you’ll put a few drops of the solution into a little hole, then insert your swab into the hole, twist it around a few times, and wait 15 minutes for results. As you can see in this photo, you’ll read your results in a little window with a test strip with a control line and a sample line. The sample line’s darkness may vary, but even a faint line should be considered positive.
With the Quidel QuickVue at-Home OTC COVID-19 Test Kit, you’ll swab your nose and then insert the swab into a little tube filled with a testing solution. You’ll swirl the swab around and then dip a testing strip into the tube to test the sample. After 10 minutes, you can check your results. The test strip will have a control line, and if a second line appears (also known as a test line), no matter how faint, it should be read as a positive result.
Similar to many other at-home Covid tests, with the FlowFlex COVID-19 Antigen Home Test you’ll get a swab, a tube with solution, and a test. Swirl the swab around each nostril to collect your sample and then swirl it in the solution-filled tube. Close the top of the tube and then drip four drops into the little window on the test marked “S” (for sample). Results will appear within 15 minutes, and if you see both a control line and a test line, whether it’s dark or faint, the test is positive.
What sets the On/Go 10-Minute Covid-19 Antigen Self-Test apart from most of the other at-home Covid tests is that it comes with access to an app that will help you read your results. You’ll follow a similar process as the other tests, swirling the swab around the inside of both nostrils, dipping it into the test solution, and then placing a few drops of the solution onto a test. Then, after about 10 minutes you can use the app to take a photo of the test and it will let you know if it’s positive, negative, or invalid. The app is nice because it also tracks your testing history and offers the ability to share your results with other people.
Yes, this is actually a photo of a negative Covid test result, but it’s still helpful. When you use the Lucira Check-It Covid-19 Test Kit, you’ll insert batteries into the test reader to ensure it’s ready to go (a green light will appear next to “ready” at the top). Then, you'll set (don’t push) the testing vile into the test unit and let it sit there while you use the test swab to collect your sample in each nostril. Once you’ve finished swabbing your nose, insert the swab all the way into the testing vile, until you feel it touch the bottom. Close the vile and push it down into the unit until you hear it click. The ready light will begin blinking to indicate that it’s running the test. The test will take around 30 minutes, and you’ll know it’s complete when a green light appears next to “done” on the top right of the unit. If the test is positive, a green light will appear next to “positive” on the testing unit, rather than next to “negative” like you see in this photo. If both “positive” and “negative” light up, the test is invalid.
If you ordered the free at-home Covid tests through the federal government, you may have received the iHealth Covid-19 Antigen Rapid Test. It works similarly to most others on this list. You’ll swab each nostril of your nose, then put the swab in a tube with a testing solution. Then, you’ll close the tube, which will convert it into a dropper, and place three drops in the small oval sample window. Results will appear in 15 minutes, and if there is any kind of line under the “T” then you have a positive result. As you can see in this photo, the positive “T” line can appear darker than the “C” (control) line, the same color, or much lighter.
With the Ellume Covid-19 Home Test, you don’t have to worry about reading your own results, because there’s an app that will do it for you thanks to Bluetooth technology. After you take the test, it will process for about 15 minutes before the result pops up on your phone through the app.
It’s worth noting that this test doesn’t have great reviews online, so if you’re on the hunt for an at-home Covid test, be cautious with this one.
For the CLINITEST Rapid Covid-19 Antigen Self-Test, you’ll swirl the swab around the inside of each nostril and then swirl it around the included testing tube six times before letting it sit for one full minute. After the minute has passed, remove the swab and place the dropper top on top of the tube. Add four drops of the sample to the test (the round dot with an “S”) and wait 15 minutes. If two lines appear on the test, then it’s positive.
A positive result on the InteliSwab Covid-19 Rapid Antigen Home Test can potentially look a bit different than most other home tests, so it’s very important to read your results carefully. As you can see in this photo, if a test line is present at all, whether it’s dark, light, or visible without a control line, it’s considered a positive reading. The missing control line can be somewhat confusing, so if you glance down at your results and see a single line, it’s really important to double-check to make sure it’s next to the “C” and not the “T” (a control line with no test line is a negative result).
With the Access Bio CareStart Covid-19 Antigen Home Test, you’ll collect your nasal sample on a swab and mix it with the testing solution in the provided tube. Next, place the dropper on the top of the tube and add three drops of the sample/solution to the square sample window on the test. Your result will show up within 15 minutes, and if you see a test line of any kind, no matter how dark, the test is positive.
Much like other at-home Covid tests, the Celltrion DiaTrust Covid-19 Ag Home Test uses a nasal swab to collect a sample for testing. After you’ve swabbed the inside of both nostrils, you’ll mix your sample with the testing solution in the tube provided, add three drops of the solution to the circle sample window on the test and wait 15 minutes for results. If two lines appear, regardless of how dark the test line is, you are positive for Covid-19.
The BD Veritor At-Home COVID-19 Digital Test Kit uses an app to deliver your test results to you (check to make sure your phone is compatible with the app before purchasing the test, though). The process for taking the test is the same as most of the others, a nasal swab, test tube, and dropper, but when the 15 minute waiting period is over, instead of reading the results yourself, you’ll scan the test and the app will read it fo you.
Claiming to be the most accurate at-home Covid test, Cue Health’s test is a molecular Covid test, but not a PCR. Rather, this test a “nucleic acid amplification test (NAAT), designed to detect the genetic material in SARS-CoV-2.” Used by everyone from NBA players to Oprah Winfrey, this is definitely one of the fancier Covid tests out there, and it comes with a price tag to match. Their Cue starter kit — which includes the reusable Cue reader (which you need to read your results) and three tests — is $444.
With a shelf life of six months, this rapid antigen test from Boson biotech will be very familiar to anyone who has done a Covid test at home before. Nasal swab, wait 15 minutes, check your results. If you’re asymptomatic, it is recommended that you perform the test at least twice over the course of three days for the most accurate results.
Like the Cue Covid test and the Lucira test, the Detect Covid test is a molecular test — a NAAT, like the Cue — meaning it’s more accurate than the antigen tests, and — yes — more expensive, too. However, it’s not as pricey as the Cue — a starter kit, with a reusable hub and single Detect Covid test will set you back $55. It’s pretty simple to use, too. You'll take a nasal swab in much the same way that you would with an antigen test, then put the sample in the Detect hub to be processed. From there, it takes a little over an hour to get your results, which will appear on your phone when they’re ready.
There’s something about this FDA-approved rapid antigen test from InBios International that seems a bit simpler than the others — maybe it’s the clunky “cassette” that shows your results, or the bright colors? Regardless, this at-home Covid test is easy to use and very affordable. They suggest that you only need to insert the swab 1/2 an inch into the nose — and even less for little kids — to collect the sample, which also feels a little more doable than some of the others.
All test results in this photo show a positive result — even the faintest second line means positive. The MaximBio ClearDetect at-home Covid test is FDA approved for use on people over 2 years old — with the caveat that an adult does the sample collection if the person being tested is under the age of 14. The shelf life of this test is eight months, and results are ready in 15 minutes.
“Testing is an important tool to limit infections to others and we need to continue to develop strong testing capacity in the U.S.” Denny reiterates. Using these photos of positive Covid test results as a point of reference can be very helpful in determining whether or not you’re positive for the virus. If you see any indication of a positive result — even a super faint second line — you should assume you have Covid and check in with your health care provider.
Thomas Denny, MSc, MPhil, Professor in Medicine at the Duke Human Vaccine Institute at Duke University School of Medicine
This article was originally published on March 28, 2022
