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Ellume COVID-19 Home Test Goes High Tech

In retrospect, I had been feeling unreasonably chilly all day, and my evening run with friends was a struggle. I attributed my sluggishness and muscle pain to the previous day’s speed workout, but shortly after finishing, I started to ache all over and shiver uncontrollably. Our traditional pizza and cider weren’t going to happen, so we made our apologies, and Tonya drove me home. After a shower, I went straight to bed, where my fever spiked and I slept poorly. By morning, the fever had receded and I felt drained but otherwise reasonable.

I’m fully vaccinated against the coronavirus (as are 64% of adults in Tompkins County) and haven’t interacted with unvaccinated people indoors recently, if at all. Nevertheless, it was impossible to ignore the possibility—however low—that I had suffered a breakthrough case of COVID-19. Some research revealed that several rapid antigen tests for COVID-19 are now available, and an MIT Technology Review comparison pushed me toward the Ellume test, available in the US for about $40 at CVS drugstores and online from

Ellume COVID-19 Home Test Kit

Now, I know you might expect TidBITS to cover computer viruses and anti-malware apps, but coronaviruses and COVID-19 tests? What struck me about the Ellume test was just how high-tech it was, and the company did a good job of employing that technology to make the somewhat complicated process more straightforward. Plus, the results went straight to my iPhone—no need to squint at a faint colored line to see if I was pregnant sick. (The competing BinaxNOW Self Test doesn’t appear to provide as much guidance and relies on the colored line approach.)

Ellume COVID-19 Home Test animation of stepsIt was a fascinating experience. Downloading the app felt a little unnecessary at first, but given all the parts and pieces of the kit, I appreciated how it walked me through the process. In fact, it forces you to watch a video that explains the entire process, emphasizing that you should not try to perform the test while watching. The step-by-step instructions come next and are wonderfully clear and concise, with additional tips and warnings sprinkled throughout.

In essence, you put some liquid in a custom dropper, use a custom nasal swab to swab the inside of both nostrils (uncomfortable but not painful), and then screw the swab into the dropper. Next comes the Analyzer, which you pair to your iPhone using Bluetooth by holding down a button on one end. Then you carefully squeeze five drops from the dropper—which has internally mixed with the swab—into a hole on the other side of the Analyzer. Let the app work for 15 minutes without interruption for your result.

My test was negative, thank goodness, and two days later, I felt fine.

Pros of the Ellume test include:

  • Relatively low cost at about $40
  • Wide US availability through CVS and online ordering (BinaxNOW is also available at Walgreens)
  • Claimed accuracy rates over 90% for both positive and negative samples, and for symptomatic and asymptomatic individuals
  • Analyzer checks for other proteins as a verification that you swabbed sufficiently
  • Results come back in 15 minutes; the entire process takes about 45 minutes
  • Only one test required (BinaxNOW requires two, 36 hours apart, for maximum accuracy)
  • The emailed test result may be useful as proof of a negative test (BinaxNOW essentially works on the honor system)

There are cons as well:

  • Nearly twice as expensive as the BinaxNOW test, which is about $25
  • Heavy on materials and packaging for a single-use test (the Analyzer refuses to work even a second time)
  • Requires downloading an app and providing some personal information
  • Precision required in the testing process
  • Numerous requirements for test accuracy (temperature range, no direct sunlight, no other tests taking place nearby, and more)
  • Closing the app during the process ruins the test and requires a new kit

Ellume COVID-19 Home Test email results

Given that breakthrough infections are happening, particularly with the Delta variant, I think there will be a role for at-home rapid testing for some time yet. It’s not that breakthrough infections are likely, but we’ve spent so much time worrying about COVID-19 for the past 15 months that any viral infection with similar symptoms will immediately cause concern. Given that the gold-standard PCR tests take a day or two to return results (and may require self-quarantining in the meantime), I plan to keep an Ellume test handy, just for peace of mind.

Besides, I already have the app installed.

More generally, I could see a bright future for in-home test kits. Ellume has developed a single-use flu test that sounds similar to the COVID-19 Home Test. The flu isn’t as contagious or dangerous as COVID-19, but the virus—often abetted by opportunistic secondary infections—can be deadly. Even when it’s not, it can lay out a healthy person for weeks and require months of recovery. The last time I had it, I felt terrible for two weeks and couldn’t kick the cough and fatigue for almost a month. TidBITS contributor Glenn Fleishman had a four-month recovery after contracting the nasty 2017–2018 flu season variant. Being able to identify a flu infection quickly without having to get to a doctor might be welcome for short-term planning and for requesting a Tamiflu prescription.

Ideally, such test kits wouldn’t be single-use. Security Editor Rich Mogull, who is also a paramedic, told me that the problem with multiple-use tests is contamination, both from previous tests and exposure to the environment. To prevent that, every piece of the Ellume kit came packaged in a separate mylar wrapper, and the instructions say not to open them until you’re ready to perform the test. When you’re done, there’s nothing to do with the plastic parts but recycle or trash them. It’s hard to know which is better, given the plastic industry’s decades-long campaign to convince us that recycling is economically feasible, something that has apparently never been true. It’s just offensive, though I suppose less so than many other modern products (I saw the plastic parts of a microwave dinner for the first time recently—insane).

I’ll bet plenty of people would pay for a home testing device that could detect multiple diseases. Some quick searching shows that these sort of things do exist, but they’re like the minicomputers of yesteryear in size and price. Even this “compact multiparametric immunoanalyzer” weighs 88 pounds (40 kg) and costs almost $15,000 refurbished.

I’m as far as it gets from an expert in this field, but Ellume has shown infectious disease testing can be brought to the home, and my money is on the tech world making this possible within my lifetime. And if I’m wrong, I’ll be dead and won’t care.

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Comments About Ellume COVID-19 Home Test Goes High Tech

Notable Replies

  1. Nice review. Glad to hear the results were negative. Hopefully it was just a 24-48 hour bug, which we all get from time to time.

  2. I’d say this would have been great if it came out a few months ago, but with the delta variant on the rise, and less than 70% vaccinated, we might be needing this in bulk once again.

    It is true individual tests must produce a lot of disposables, but this very same test could also be employed by clinics too. That’ll give a fast response, less consumables, cheaper costs, and help for those who are too technophobic or don’t own the right tech to do the test themselves.

    Israel is about 80% vaccinated, and they’re having a surge of corona virus cases due to the delta variant. It’s mainly affecting the under vaccinated population — the extreme religious groups who insist it’s all a hoax and the Muslims who don’t trust the government (sounds familiar?).

    Fortunately, we know the current Pfizer (and Moderna) vaccines are effective against the variant. Never the less, they’re looking towards another lockdown in Israel.

  3. I believe it’s 80% of their adult population that’s vaccinated. Many of their current cases however are among children and teenagers. We need to keep in mind that even today, there are no vaccines for younger children. And 12-15 was only recently approved. This would make us adults all getting vaccinated just that much more important.

    The good news is that among children symptoms are often weak (or not present at all) and serious illness is very rare. Just this morning I learned that although Israel has recently seen incident rates grow, their hospitalization is still declining. The primary explanation is that hospitalization is usually only a risk for adults and seniors. Fortunately, vaccination among seniors is high and efficacy even against delta is very high for the mRNA vaccines.

  4. I’m glad it wasn’t more serious. Stories about long-haul survivors scare me more than stories about people dying. I know the vaccine is supposed to make any subsequent infection less severe, but does it also reduce the chance of a long-haul recovery? I understand that some long-haulers were never that sick to begin with, but just stayed the same or even got worse as weeks and months went by.

    Thank you for that information.

    I see that the Ellume web site tells me to go to the Azova web site to buy a kit for international travel, and the Azova web site offers to sell an at home antigen test “from $50”. No doubt the international virus has more expensive tastes than the domestic one.

    More seriously, how large is the package? Is it so large as to make it unfeasible to carry one or two when traveling to avoid needing to purchase test kits at the destination?

    Unrelated to the article, what does a poor traveler do when a test returns a false positive?

  5. Sadly, after two days of feeling fine, and even running a 1500m race, I felt lousy on Sunday again. Today I was better in the morning but faded. Still no real fever or symptoms apart from fatigue. The go-to test for weird symptoms around here is Lyme disease (I’ve already pulled five or six deer ticks off this year, though they never, as far as I know, stay on long because they make me itch badly). My doctor didn’t even blink at calling in a referral for a tick-borne disease panel. I’ll know soon enough if I have a course of doxycycline in my future.

    Indeed. Even if the vaccines protect you from serious cases of COVID-19, who in their right mind (yeah, yeah, I know) isn’t going to worry about any illness being COVID-19 at this point?

    You and me both. I don’t think we have enough time with vaccines to know if breakthrough infections could result in long-haul COVID.

    The Measure app tells me it’s 6.5 inches high by 4 inches wide by 2.5 inches deep. It’s light, and you could easily unpack the box and pack all the parts more efficiently. I see no issue with traveling with it, perhaps apart from the fact that the Analyzer has some sort of a battery.

    If I were to get a positive, false or otherwise, I’d immediately get a PCR test. There is a false positive rate of either 4% if you have symptoms or 9% if you don’t. False-negative rates are lower: 0% for symptomatic cases and 4% for asymptomatic cases.

    I think it’s just like a pregnancy test. If you get a negative result and you’re really worried, you take it again, and hopefully a second negative sets your mind at ease. If you ever get a positive result, you go see a doctor right away.

  6. A rash is usually one of the warning signs of Lyme, as are circular or bulls’ eye marks where the tics bit a victim. But these symptoms vary, and some people don’t show them at all, so a test is a very good idea. I’ll keep my fingers crossed, and I hope whatever symptoms you have will vanish soon.

  7. As @ace says above, you would be advised to get a PCR test right away. At least then you gain some clarity. Your travels, however, will most likely be delayed. Here in the States it’s very hard to find a PCR test with guaranteed

    I was wondering about exactly this case when I recently went on international travel. Usually, the requirement is the test is less than 3 days old prior to travel. So assuming your antigen test came back positive on day 3 before travel (it’s a quick test after all), even if you then right away get a PCR test (assuming slots open, no wait time), you’re looking at day 1 before travel at best. If you’re less lucky the negative PCR result will come in just after your original itinerary departed. Of course, a negative PCR result is still great news, but I would assume you will have to engage in some rebooking or at the very least some super last-minute nail-biting right up to the wire. ;)

    I was pleasantly surprised when I ran into a testing opportunity two weeks ago at ZRH airport. The Swiss have a walk-in testing site there that guarantees PCR results within just 5-10 hours. It’s not cheap at about $170, but that’s still a factor 3 less than what I get quoted around the Bay Area for a PCR test with guaranteed 24-hr turn-around.

    On a related note, it’s good to keep in mind that several countries will not accept antigen tests for entry, only PCR. The US is fine with antigen though for re-entry which is convenient because it’s a fast and cheap test. But as others have pointed out, it’s by far not as accurate as PCR which is why that is still considered the gold standard.

  8. Thanks for testing, and providing a review of, this product. I am pleased that the device has given you a negative result. Just as a check, maybe a comparison test at a clinic would have been advisable, particularly as you subsequently experienced flu-like symptoms.

    Here in Australia, the rollout of the vaccines has been less than admirable with politics and idiots getting in the way. The value of vaccination was again proven in the last few days with the local example of a house party of about 30 people testing positive except for the six who had been vaccinated.

    I’ve had my two jabs of the Astra Zeneca vaccine and played two good games of golf almost immediately after taking the shots. But Astra Zeneca vaccine is under a cloud due to the rare possibility of blood clots and so people are resisting taking this vaccine despite the statistics showing the higher likelihood of getting the virus and of women getting blood clots from contraceptive pills.

    Home-testing applications for other symptoms is an interesting and potentially excellent development.

  9. You stated that the test results are ‘accepted.’ PLEASE make clear to your readers that home testing is NOT accepted at airports, and, at least for an international flight, you would almost certainly be turned away and sent back home.

  10. I’d be getting that antibiotic if there’s a slightest chance of Lyme. Early intervention being key, it too has a long term life. My wife suffers from it for the past five years, symptoms sporadically appearing all from initial tick bites in the forest upstate in New York. She had a quick set of antibiotics but it still became an issue.

  11. Adam, thanks for this brave piece, so glad you’re COVID free — but (being a regular visitor to tick infested QLD in Australia) can I join others here in saying don’t take risks with Lyme!

    It’s freezing out with a 70mph gale, but there are times when being in the S Island of NZ feels OK… :slight_smile:

  12. Glad your immune system took care of you, Adam. Being ‘vaccinated’ will protect you even from variants so not sure about the ‘panic.’ Also, not sure where you live, but, Lyme Borreliosis is a real entity esp in states like Wisconsin and Pennsylvania. Erythema chronicum (migrans) is the red bullseye exanthem (rash) commonly seen, but the eruption may not be annular (a ring), it maybe circular (filled in circle). Also, STARI which is Southern Tick Associated Rash and Illness is tick related but NOT Lyme disease and not necessary to treat. It is seen in southern states but variants are spread across the US as well. So, a rash after a tick requires a medical differential diagnosis followed by reasonable and logical course of action to confirm or deny. To truly test for Lyme is not an easy process requiring two or more tests to CONFIRM each other, so to speak. Doxycycline is such an easy drug to take, but watch for photosensitivity and exaggerated sunburn if you get in the sun. (I’m a dermatologist). As well, children and teens do well with Coronavirus and are ‘sick’ for a short time, as all my grandkids revealed. These are generalities and not written in stone, not a treatment suggestion, and not medical care you should follow: these are my thoughts as a Medical Doctor, not a politician. :slight_smile:

  13. Agreed! Lyme is pretty much epidemic here in upstate New York, so I know many, many people who’ve had it, and Tonya had another tick-borne disease a few years ago (anaplasmosis). At this point, I think the bullseye rash is quite rare—if you get one, that might be indicative, but most people don’t. Most don’t even know they’ve been bitten by a tick. That’s not my problem because tick bites make me itch, so I notice them quickly.

    I had been thinking that too, but my doctor doesn’t seem to think it’s at all likely, given that the only real symptoms I’ve had are fatigue and occasional temperatures slightly over normal. We’ll see as the tests come back this week.

    No, I said: “The emailed test result may be useful as proof of a negative test (BinaxNOW essentially works on the honor system)”

    I haven’t attempted to travel internationally nor did I try to figure out the various regulations from different countries. That’s left as an exercise for the reader.

    Oh, I’m so sorry! One of Tonya’s cousins has suffered with symptoms that may have been the result of a case of Lyme for the last decade. My doctor said that if it were him, he’d wait until the tests came back to start the doxycycline because my initial labwork didn’t show any major indications of infection. But, he said, if it got worse in the next few days, take it! :-)

    Thanks for the details and the suggestions—I appreciate the kind thoughts from everyone here!

  14. United Airlines has worked out a deal for the BINAX test where UAL will accept the results for re-entry to the US. It’s not clear if the Ellume test would be accepted by airlines or TSA. Nor do I know if other airlines would accept BINAX.

    Fortunately, Europe dropped their entrance test requirements for vaccinated people a couple weeks ago. So we cancelled the pre-flight test we had scheduled. We’re still scheduled for an airport pre-flight test coming home. (Test standards are strict, 48 hours for Antigen, 72 for PCR tests. Last I heard, Hawaii was only accepting PCR tests, not antigen. Check with your airline, but -good luck getting through to them-!.)

  15. Of course, I wouldn’t know that a positive result was false, but my question was based on the assumption that it was. As @Simon said, it would be a significant inconvenience to a traveler.

    By Europe, I assume you mean the EU or that my information is out-of-date. My understanding is that England requires a pre-flight negative test followed by quarantining on arrival with follow-up tests on day 2 and day 8. (There is an optional test on day 5, after which quarantine may be broken, but the day 8 test is still required.) Of course, all tests must be negative, and therein lies the problem.

    If there is a false positive rate of 9%, then I have a 91% of not getting a false positive. But if I need three tests, now the chance of getting zero false positives is 0.91^3, or an almost 25% chance of getting one or more false positives. That’s bad odds when I want to go sightseeing. And if I take the optional test on day 5 to try to leave quarantine early, now I have a 31% of a false positive at some point. Sigh.

  16. Yes, that’s right, sorry. From what I understand, UK was going to open up and then changed. Each EU country has adopted the EU -suggestion- at a different rate/different mechanism.

  17. Interesting article, thanks for taking the time to write up your experience Adam, even as you weren’t feeling 100%. Question as I’m not sure about all the terminology… is this the same as a lateral flow test?

    Over here, we have PCR tests (as discussed above) and lateral flow tests. Both are free, and I know people who keep a box of lateral flow tests (one box contains 7 tests I believe) handy in case they feel ill and want to check. In that context, $40 seems quite pricey, especially as you might need two or three on hand in case of multiple people in a household feeling ill. Is this a different type of test, or are test kits generally expensive in the US? Even $25 for lateral flow is more than I expected – I assumed retail price would be $5-$10/test. That’s why I’m wondering whether this is a different kind of test to the ones I’m familiar with.

  18. OK, I’m officially old now that I’m sharing my medical woes as general conversation, but since I started this whole discussion by taking a COVID-19 test after feeling sick, I feel I need to close the loop.

    My tests came back from the Mayo Clinic yesterday and I tested positive for babesiosis, which is a tick-borne disease that often accompanies Lyme and does indeed have as its main symptoms fatigue and malaise with chills and fever too. Nevertheless, it’s unusual enough around here that my doctor had never treated a case.

    Unlike Lyme, which just gets a course of doxycycline, babesiosis requires both the antibiotic azithromycin and atovaquone, an anti-malarial drug, since it’s actually a parasite. (And I have to say, atovaquone is disgusting—it’s bright yellow, is vaguely representative of banana cough syrup, so thick and chalky that it gloops rather than pours, and has to be taken using a spoon rather than a little measuring cup because it sticks to the side.)

    Happily, even before I got the diagnosis and started the drugs yesterday, I was feeling normal again. With luck, it’s all upswing from here.

  19. Glad you got sorted Adam. Thank goodness for science.

  20. Welcome, neighbor.

    I’m really glad you found out what it was and are getting better.

  21. The atovaquone does sound awful, but I’m very glad to hear they’ve been able to give you a definitive diagnosis and treatment. Good luck in your recovery and thanks for letting us know how it turned out.

  22. It’s been interesting to read this commentary about Lateral Flow Tests.

    In the United Kingdom the National Health Service (NHS) supplies LFTs free to everyone who wants them. You can pick up a box of 7 tests from a pharmacy, or order online, and have them delivered to your home for free. Each LFT is uniquely serialised. The QR code of the LFT is scanned on your smartphone using the NHS web app, and then you report the result, which helps the NHS understand the spread of the virus.

  23. I’ve heard from Ellume that their test is also now available on Amazon. (At the time of writing, it was out of stock, so I didn’t mention it in the article since I had no way of knowing how permanent that state was.)

  24. I had an interesting email exchange with David O’Connor, a longtime TidBITS reader who’s also a virologist. He shared some interesting details about the BinaxNOW test, which is apparently a better test than I had given it credit for being.

    I do so enjoy hearing from experts!

    He first wrote:

    The emailed test result may be useful as proof of a negative test

    YMMV on the acceptability of any antigen test. Many travel programs require a molecular test. Some states, including Wisconsin where I live, require confirmatory molecular tests when someone who has symptoms tests negative on an antigen test for decision-making.

    Only one test required (BinaxNOW requires two, 36 hours apart, for maximum accuracy)

    Two tests is an advantage to BinaxNOW. The reduced sensitivity of antigen tests relative to molecular tests comes from the time it takes for antigen to accumulate during infection. Testing a few days apart increases the reliability of the test. In fact, we’ve been trying (admittedly without much success thus far) to make serial testing an alternative to antigen + molecular testing on the same day for K-12 schools. Last year, we implemented on-site BinaxNOW testing in more than 100 local K-12 schools. It’s a great test because of its simplicity.

    no need to squint at a faint colored line

    If you’ve ever seen or used a home pregnancy test, BinaxNOW is just as easy to read. In all of our training, we had one very faint line that made us re-run a test. I’d encourage you to try a BinaxNOW test too if only to get a point of comparison. The Ellume test is fine, and I’m glad you liked it, but two BinaxNOW tests might be a tad better from a sensitivity perspective and are more economical.

    And when the discussion got into more detail about test sensitivity, he wrote:

    Testing “proof” is clear as mud. It varies from place to place. Because the guidelines are contradictory, even within a single place there can be different interpretations of the rules. We’ve been really involved in figuring out what sort of tests should be allowed for students to return to school after having COVID-like symptoms…and it’s a mess. I’d say that figuring out how to use testing optimally is the proverbial million-dollar question for the upcoming school year, but that understates it - the Biden administration has allocated ~$10b to support school reopening this fall.

    The 36 hours isn’t quite because the second test is necessary for BinaxNOW to be useful. Rather, it is because it takes an already excellent test and makes it better. To understand why, it helps to understand how the virus replicates in your body. When you get a PCR test, the result is reported in “cycle thresholds” or Ct, which is inversely correlated to the amount of virus in your sample. Someone who has a positive PCR test with a Ct of 35 has much less virus in their sample than someone whose Ct is 15. The biggest difference between PCR tests and antigen tests is that PCR tests can sensitively detect viral genetic material when PCR Ct is between 30-40. Both types of tests reliably detect infections when the Ct <= 30. I say that antigen tests are already excellent because capturing people whose Ct <= 30 will capture the vast majority of (if not all) people who are both infected and are shedding enough virus to be contagious to others.

    Now, why does serial testing make sense? Because virus shedding is asymmetric. We know this from the daily testing of NBA players and staff during their bubble in spring/summer 2020. Scientists used this data to model virus shedding. The y-axis is Ct value, and the horizontal line shows the Ct ~ 30 threshold where antigen tests become sensitive:


    If someone’s test is above the red line, they would be positive by both antigen and PCR tests. The worrying case is when someone is around day 3 and is positive by PCR, but negative by antigen test. The 36 hour serial testing takes advantage of the rapid upward slope, so that someone who is negative on the first test would be positive on the second antigen test.

    Rich is almost certainly talking about Ct values < 30 when he says that it works better when the viral load is at the right level. Faint bands correlate with minute amounts of antigen, which typically mean either (1) someone would test strongly positive if retested in 24 hours or (2) they are past the period of peak viral load and contagiousness to others.

  25. Two updates after the article was read by some folks on another list I’m on.

    A post talking about the different types of COVID tests:

    The poster (a molecular pathologist specializing in COVID-19 testing) noted:

    I especially appreciated the insight you shared from Dr. O’Connor, the virologist, in the comments. The only thing I would add to his comments would be that the Ct value from PCR testing is variable between different assays. So the Ct from the test in one lab will only roughly correlate with the Ct from a different test in that lab or another lab.

    And a second person pointed that another rapid antigen test has just received the emergency use authorization from the FDA. It may not yet be in stores, but it will provide another option.

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