Finding the Best At-Home STD Test

Getting tested for STDs is an intimidating prospect for many people. The U.S. as a whole has a lot of strange shame issues around sexuality, and even the most confident among us cringe at the thought of a long swab inserted somewhere very sensitive (this is no longer a standard testing method).1

But few things in our lives could be more critical than regular STD testing, both for short-term comfort and long-term health. Luckily, with the proliferation of new direct-to-consumer STD test kits, screening yourself or a loved one in the privacy of your own home has never been easier or more comfortable.2

We thoroughly tested and evaluated each offering from the top at-home testing companies. The guide below will tell you which ones excel at everything from accuracy to customer support, and it should help you decide which provider is right for you.

We believe there are four companies worth considering in the STD testing space: LetsGetChecked, Everlywell, myLAB Box, and STDcheck. Three of them allow you to collect your samples at home and mail them in, while the fourth is a hybrid model that provides anonymous in-person sample collection at any of their affiliated labs. Whichever company you choose, you’ll find friendly and efficient customer service, as well as accurate and reliable tests with results in as little as two days.

Some of these platforms test for far more than STDs, but in this guide, we focus on exploring and comparing strictly their STD testing options.

At Innerbody Research, we extensively test each health service we review, including all of these at-home STD testing services. All told, our team has spent over 190 hours testing and researching their STD test services. We’ve ordered these tests and performed them on ourselves to give you a thorough picture of the customer experience, from ordering to blood drawing and, finally, to results and clinical support.

Along the way, we’ve read through more than 100 scholarly articles on STDs, STD testing methods, and treatment so we can confidently tell you which companies are using the best methods and providing the best care. Additionally, like all health-related content on this website, this review was thoroughly vetted by one or more members of our Medical Review Board for accuracy.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions to live healthier lifestyles.

To evaluate STD tests, we set out to define a set of criteria that would convey the most critical information to a potential user. These include test variety, cost, speed, kit quality, and helpfulness.

While accuracy is vitally important in STD testing, the truth is that the methods used by all of these companies boast accuracy percentages in the high 90s. There's little meaningful difference among them in this regard, though different testing methods can cause results to take longer, which is why we included speed in our criteria.

Let’s have a closer look at each to see which company might be the right fit for your needs.

Test variety

Winner: myLAB Box

This was a close one. Each company has subtle differences in their offerings, and even myLAB Box isn’t perfect (no herpes simplex 1 test or early HIV detection). Ultimately, it has more overall tests than anyone else, and it offers many of them in well-conceived bundles. We recognize that these bundles may seem like overkill to some people and that the bundling does raise the price. But from a safety perspective, we can’t forget that many STIs and STDs occur concurrently and increase the risk of catching others.11 So, for most people, buying even a basic bundle like the Safe Box or the three-site chlamydia and gonorrhea test is a wise move.

STDcheck allows you to mix and match individual tests you can take in a single lab visit, which is nice if you've had a partner who reports multiple specific infections for which you want to test. But as we'll discuss in our cost section, it might be wiser to stick with a panel from an at-home testing company.

Cost

Winner: Everlywell

From a pure cost perspective, Everlywell has some of the lowest prices out there. It used to offer a membership program that allowed you to take almost any test on its site each month for just $24.99, but that program has been eliminated. Still, its STD test prices are consistently lower than most competitors’ options. The trade-off, which we’ll discuss below, is speed.

If all you need is a single test for one potential infection, and you don't mind an in-person lab visit, STDcheck can sometimes be a nice option. It lets you pick from a menu of tests that sometimes cost less each than you’d pay for a small panel of tests elsewhere, the whole of which you might not need if you’re only looking for one STD. And its 10-test panel (without its early HIV detection) is one of the best deals around. But for certain other tests, or when you start combining two or three tests from that menu, the price quickly eclipses what you’d pay for a small panel from a competitor.

Here’s what that looks like in a handy chart:

Note that the pricing above reflects the use of the following discount codes that are available to you:

• myLAB Box: Code INNERBODY20 saves 20%
• LetsGetChecked: Code INNERBODY25 saves 25%
• Everlywell: Code INNERBODY15 saves 15%

Speed

Winner: LetsGetChecked

For most tests, LetsGetChecked had the best shipping speeds and results turnaround for the majority of our testers. The company says most shipments will take up to five days, and they offer express 2-day shipping for an added cost. Our testers selected free standard shipping, and most of their tests still arrived in just two days. For the delivery of results, most companies offer 2-5-day processing for tests once they arrive at the lab, but our testers consistently had their results in 1-2 days after lab arrival. LetsGetChecked also provides tracking in both directions so that you can follow your test every step of the way.

There were some instances where myLAB Box kept pace with or slightly edged out LetsGetChecked, including for herpes testing. But these companies often rely on affiliate labs around the country. Some testers on the West Coast got their results faster when the lab involved shared their time zone. Shipping across the country always added a day or two to the overall process.

Communication speed is also an area in which LetsGetChecked excels. It has plenty of customer service reps ready to answer the phones, and they’re knowledgeable enough that none of our testers ever needed a transfer to a lab tech or manager; the reps were able to answer even our most complex questions with ease.

Again, though, myLAB Box was a close second in support speed, with a convenient chat feature that can answer a lot of simpler questions with ease. Some slightly more complicated questions that LetsGetChecked was able to answer on the phone required email support through myLAB Box.

Kit Quality

Winner: Everlywell

Despite being our winner for cost, Everlywell still provides its customers with the best kits we’ve used. For the most part, these kits bear striking similarities to one another. You typically get the following for an STD panel:

• Urine collection cup and vial
• Blood vial or blood spot card
• Retractable automatic lancets (for finger pricking)
• Alcohol wipes
• Adhesive bandages
• Gauze

LetsGetChecked and Everlywell are the only two companies to give you a pipette to help you collect your urine sample without the risk of spilling. But Everlywell’s kit uses a collapsible, reusable silicone collection cup instead of the simple, plastic-lined paper cup that LetsGetChecked provides. What you’re supposed to do with a reusable cup after you submit your sample is a mystery. It seems like a waste to throw it out, but how many people are going to pop it in the dishwasher and use it as a drinking glass on their next picnic like we did?

Everlywell and myLAB Box are also the only two to provide full-size adhesive bandages. LetsGetChecked uses those small, circular bandages that do not stay in place. All of this reveals that Everlywell’s kit construction is just a little bit better than anyone else’s.

Helpfulness

Winner: myLAB Box

What will your results look like? What will you do when you get them, especially if you test positive for one or more STDs? myLAB Box excels at presenting its users with results that are easy to understand, and it doesn't place financial barriers between you and treatment from a physician.

With results from LetsGetChecked and STDcheck, it isn’t immediately clear what your results were. LetsGetChecked uses terms more complicated than a simple ‘Positive’ or ‘Negative,’ and the font and placement of this information on the results page are small and obscure. And STDcheck delivers its results through its sister company, HealthLabs, which can be confusing to some users.

With Everlywell and LetsGetChecked, you can have a free consultation with a clinician if you test positive for any STD. But if you don’t test positive, you’d have to pay for a telehealth consultation from either company. And with LetsGetChecked, even if you do test positive, you can’t get a prescription unless you pay extra to be referred to a LetsGetChecked physician.

myLAB Box takes a different approach. You can request a physician consultation no matter your results, and they’re always free. That can be critical if you have definite symptoms and still test negative, as a physician can advise you whether to retest. You don’t have to pay anything extra to get a prescription, either.

There are certain things you can do to decrease your odds of contracting an STD. Consistent condom and dental dam use go a long way, but you shouldn’t rely on that alone. Regular testing is one of the best ways to ensure that you aren’t about to spread the infection to an intimate partner, and if they regularly test as well, you’ll be that much safer.

STDs are widespread

According to Planned Parenthood, a staggering 50% of Americans will contract an STD by age 25.3 While half of the 26 million Americans who get a sexually transmitted infection this year will likely be younger than 25, this also means that roughly 10 million of those people will be older than 25.4 If you are sexually active, testing matters — regardless of your age.

Unfortunately, some STDs are notably on the rise in America. Cases of syphilis rose by 17% in just one year, according to recent CDC data.5 Chlamydia, gonorrhea, and syphilis cases have increased dramatically over the past five years, with gonorrhea cases higher now than at any time since the early 1990s.

Globally, there are nearly 400 million new infections of one or more of the following STDs each year:6

• Chlamydia
• Gonorrhea
• Syphilis
• Trichomoniasis

Most STDs are treatable

Now for some good news: all four of the common STDs above (chlamydia, gonorrhea, trichomoniasis, and syphilis) are curable with readily available treatments. To get treatment, though, you need to test and discover the infection.

The sooner you know that you are infected, the sooner you can begin treatment. As with many diseases, early diagnosis of an STD means that treatment is more likely to succeed. If the infection goes undetected for extended periods, treatment becomes more challenging and complicated, and the chances of reversing the damage lessen significantly.

Some STDs show no symptoms

Many STDs go unnoticed because they are asymptomatic until the later stages of the disease.7 You can’t tell someone has an STD just by looking at them. For example, people with HIV may not develop symptoms for a couple of years after being infected. Eighty percent of people with herpes simplex 2 are never even diagnosed. Common and easily curable STDs like chlamydia and syphilis can have horrific long-term complications, including infertility and irreversible neurological damage.8 The only way to prevent future complications is to get tested regularly to ensure early detection and treatment.

Yes, you can test reliably for all STDs either at home or in a lab. Not only are these testing options more convenient than in the past, but they’re also highly discreet and accurate.

So how should you choose between testing at home or testing in a lab? The choice is partly about personal preference and comfort, though there are situations in which we advise an in-lab testing experience. Here is a handy chart to help you decide.

As you can see, there are certain situations in which in-lab testing is ideal. Note that no at-home company offers every single test out there. Below, we’ll get into each potential test type and let you know where you can get it.

Relying on a professional to conduct the test in a lab can still be useful. Even though at-home test kits use the same methods with comparable accuracy, you may prefer to have the test administered in a lab if you have nagging concerns about your ability to collect your own sample properly.

If you decide to test in a lab setting, our top recommended provider is STDcheck (see our full review to learn more).

• myLAB Box: 9.2/10
• LetsGetChecked: 9.0/10
• Everlywell: 8.7/10
• STDcheck: 8.2/10

Which company’s tests are right for you?

While we ranked these companies according to our overall impression of their performance, that doesn’t mean our top choice is right for everybody. Each company has areas in which they excel and offerings the other companies might lack. Take a look at our chart below to see which companies offer the tests or features you might need in particular.

Yes, they're highly accurate. At-home testing technology is as accurate as the tests ordered by doctors during a traditional visit, which isn’t a surprise since the tests are designed and analyzed by certified diagnostic labs. In fact, as long as you follow the instructions properly, some at-home testing can actually produce more accurate results.

• At-home tests use the same collection methodologies.
• At-home test samples are processed in the same kind of labs as in-lab tests and held to the same rigid quality standards.
• The best at-home test kits are very trustworthy. They and their components are either FDA-approved or considered by the FDA to not require redundant approval because the tests and components were designed by certified medical labs for accuracy.

There are two major caveats here, though, which we want to emphasize:

How could you get even more accurate results with at-home testing than testing in a clinic? It's because both free and for-profit clinics have to keep a close eye on their bottom line, and they have higher brick-and-mortar overhead costs. Under that kind of financial pressure, some clinics turn to tests that are less reliable but significantly cheaper to process.

For example, all of the companies we’ve included in this review utilize herpes tests that look for immunoglobulin G (IgG) antibodies. Some clinics prefer to run tests looking for immunoglobulin M (IgM) antibodies. Theoretically, these tests can detect a herpes infection sooner since IgM antibodies show up before IgG antibodies. Still, the IgM tests are far less accurate in general, and you may receive false results.9

But how accurate is highly accurate?

Most tests associated with at-home STD testing boast 92% accuracy or better — just as accurate as testing in a lab.10 Here are just a few examples from some of our top choices for STD testing (LetsGetChecked and myLAB Box for at-home testing and STDcheck for in-lab testing) to give you a good idea of their commitment to accuracy and best practices.

The herpes testing offered by both LetsGetChecked and STDcheck is 98-99% accurate — with or without symptoms — as long as you wait six weeks after exposure to ensure the infection is detectable.

Trichomoniasis is the third most common STD in the United States today — and it’s curable. If untreated, it can increase your risk of contracting HIV. myLAB Box’s trich test uses SDA (strand displacement amplification) technology to yield 95% sensitivity and 99% specificity, which is really reassuring.10

• Sensitivity is how often a person who is infected tests positive.
• Specificity is how often a person who is not infected tests negative.

STDcheck’s chlamydia and gonorrhea tests use the FDA-cleared nucleic acid amplification testing (NAAT) method. This urine test is extremely accurate, and you can take it as early as 2-6 days after exposure because it detects bacteria in the urine even before you show symptoms. Don’t be disappointed if you have never heard of it, but be comforted by how accurate it is:

• It detects chlamydia with 99.8% sensitivity and 99.3% specificity.
• It detects gonorrhea with 100% sensitivity and specificity.

HIV testing performed with any of our top recommended companies is exceptionally accurate.

The first thing to consider when choosing an at-home STD test is whether you want to use a multi-test panel or whether you want to test for a specific STD. Available tests cover just about any kind of infection you can imagine, from chlamydia and gonorrhea to hepatitis and HIV.

Generally, unless you are experiencing specific symptoms or have reason to believe that you may have been exposed to a particular STD, the multi-disease tests would likely be your best option. Many infections also occur concurrently, so it’s wise to check for others if you think you might have one.11

However, as you might expect, the individual tests are almost always less expensive. If you are in doubt, we recommend getting advice from your physician.

Of all the companies that offer STD test kits online, our three favorites are LetsGetChecked, Everlywell, and myLAB Box. You cannot go wrong with any of these companies, as they are all rated highly in terms of accuracy, privacy, and customer service.

All of the top providers offer kits that test for multiple STDs at once. Which level of multi-test do we recommend? Usually, the tests that cover chlamydia, gonorrhea, HIV, and trichomoniasis (at a minimum) are the best combination of comprehensiveness and value.

If you’d like to rule out all of the likeliest infections, you may want to spring for the most comprehensive tests, mainly myLAB Box’s Total Box or STDcheck’s 10-Test Panel. These tests come at a higher price, of course, but are a good value if you consider how much testing for each STD individually would cost. If you have concerns about particular sexual encounters, these can provide the greatest peace of mind.

Recommended multi-test kits

A good multi-test kit should be comprehensive and easy to use. myLAB Box and LetsGetChecked offer several multi-test kits for you to choose from, while Everlywell and STDcheck each offer only one. If you don’t mind having your sample collected in person, we recommend STDcheck’s 10-test panel for accuracy, speed, and value. The chart below breaks down the pricing and coverage for each company’s best multi-test panel.

The myLAB Box Total Box is the only panel on this chart that tests for gonorrhea and chlamydia at three sites (oral, genital, and anal) rather than just one (genital). Also, its HPV test is an optional $30 add-on. HPV is notoriously difficult to detect in males, which makes that add-on a poor choice for men at this time.12

Individual tests may be somewhat less comprehensive, and purchasing more than one or two will quickly add up to the cost of a complete test panel. But they can serve an important purpose.

Suppose you’ve recently tested negative across the board but afterward had sexual contact with someone who later tested positive for a specific STD. In that case, you may prefer to test individually for that infection. Standalone tests are also good for retesting after you complete a treatment course for a given diagnosis.

However, some test bundles don’t cover everything you need, and buying a standalone test can be a great supplement. For example, you may find that the Complete 8 panel by LetsGetChecked is the one you want, but you also want to test for herpes. LetsGetChecked screens for herpes simplexes 1 and 2, but only in its standalone Herpes Test. The company doesn't bundle it with any of the panels, so you’d have to buy it separately to supplement the panels they do offer.

If it’s within your budget, we almost always recommend a multi-test panel, simply because many STDs occur concurrently and because one infection almost always makes you more susceptible to another.

At-home STD testing has the potential to detect nearly everything you can expect to detect in a lab or through your primary care doctor. Here’s a look at what you can expect to find:

Best overall, most comprehensive test, best post-test treatment assistance, best bundling options

STD testing is something of a specialty for myLAB Box because it used to be the company’s sole focus. Over the years, it has branched out into other testing areas unrelated to STDs as well. One of its most noteworthy features is the way it bundles its various kits. These present opportunities for people concerned with more than one STD due to a recent exposure or those looking for something comprehensive while actively dating.

You can see how its multi-test kits compare below, with discounts you can get if you use our INNERBODY20 discount code.

Several of myLAB Box’s kits have recently come down a bit in price, including the Uber Box (down $70) and the Safe Box (down $20). The Total Box, which is the most comprehensive test in this guide, has remained the same price.

With myLAB Box, you can request a doctor’s consultation whether or not you test positive for anything on one of its tests. In cases of a positive test for Chlamydia, gonorrhea, or trichomoniasis, you can get a prescription for medication to be filled at your local pharmacy.

myLAB Box’s post-test assistance is distinct from LetsGetChecked or Everlywell in that it’s wholly free and available regardless of your results. LetsGetChecked offers a free initial consultation if you test positive, but you have to pay $39 for a consultation that could get you a prescription. And Everlywell, despite offering a free service, only provides it to those with positive results.

You can read an even more in-depth assessment of myLAB Box in our complete review.

Fastest average turnaround time and best herpes test

LetsGetChecked offers a multitude of tests in addition to STD testing. It’s a fast and reliable company with great communication, though it doesn’t have the same flexibility in testing for individual STDs as others.

Available tests include:

• Herpes Test (looks for HSV-1 and HSV-2)
• Hepatitis B & C Test
• Simple 2 (chlamydia and gonorrhea)
• Standard 5 (chlamydia, gonorrhea, trich, HIV, and syphilis)
• Complete 8 (same as Standard 5 plus gardnerella, mycoplasma, and ureaplasma)

Here is a handy chart with a breakdown of what tests the company’s kits include (note: promo code pricing is available when you use promo code INNERBODY25 during purchase).

LetsGetChecked also used to offer a three-test kit that looked for chlamydia, gonorrhea, and trich, but that has been discontinued.

LetsGetChecked is our preferred provider for herpes testing because it checks for both major herpes strains rather than just HSV-2. Given the prevalence of HSV-1 and its ability to appear as genital lesions (which many people associate with HSV-2), testing for both if you’re symptomatic or have been in contact with an infected person is critical.32

Our testers were impressed by the speed and tracking communication they found from LetsGetChecked. The company had the fastest average turnaround time from the order date to the receipt of results, though there were some instances where myLAB Box gave it a run for its money. Along the way, you can see a graphic depiction of your test’s journey on your patient dashboard, showing you:

• When your test was ordered
• When your package was shipped
• When you received the package
• When you activated the test
• When it was shipped to the lab
• When the lab received your test
• When the lab processed your test
• When results became available

This level of detail is unparalleled among competitors.

One area where LetsGetChecked has fallen short is in the evolution of its consultation system. At one point in the company’s history, you could have a free consultation after a positive test with a doctor capable of prescribing you medication. The company could even ship that medication to you and would do so for free in some cases. But LetsGetChecked has since launched its own primary care telehealth service to support its testing side.

Now, even positive test results can't get you a prescription alone. You must endure the free consultation to be referred to a LetsGetChecked physician capable of prescribing you something, and those appointments cost test takers $39. (If you visit the LetsGetChecked website and book an appointment without ever having taken a test, it'll cost you $49.)

Compared to the free prescriptions you can get from myLAB Box or Everlywell, this seems like a somewhat burdensome practice. It’s less expensive than STDcheck’s program, though, which charges $95 for a consultation of any kind, regardless of testing status or results.

If you want to learn more about LetsGetChecked, you can read our comprehensive review of its products and services.

Best budget pick

Everlywell is a home testing company that offers a wide array of tests, many of which we highly recommend. What Everlywell offers in STD testing is of high quality but is not as extensive as other companies like myLAB Box.

In addition to what you see in the chart below, Everlywell also offers individual testing for hepatitis C, syphilis, HPV, and trichomoniasis. (The chart below reflects 15% savings using our coupon code INNERBODY15.)

The male test panel utilizes urine and blood for its samples, while the female test kit relies on a vaginal swab and blood sample.

Everlywell’s HIV test is less expensive than those from STDcheck or myLAB Box, for instance, but this test only checks for antibodies rather than the dual-action test for antibodies and antigens. The company is also one of the few to offer an HPV test, and it looks for the same number of HPV strains as the myLAB Box version despite costing $20 less.

We have a complete breakdown of Everylwell’s services, as well as our testers’ experiences with the company, in our dedicated Everlywell review.

If you test positive for certain STDs, an everlywell clinician will reach out to you and can provide you with a prescription for medication to treat chlamydia, gonorrhea, or trich at no added cost. (The cost of medication is separate.) This is a nicer setup than LetsGetChecked offers, where prescription consultations cost $39, but it’s not as nice as myLAB Box’s free consultations for all test takers (regardless of results).

In our testing, Everlywell’s processing took the longest. On average, STD tests from Everlywell took about a week to process from the time we shipped them off to the lab to the time we got our results.

Best for in-person STD testing and best HIV test

STDcheck is one of the largest STD companies in the nation, if not the largest. This company has a different model, though. Rather than at-home testing with a mailed kit, you order your test at home and then come into a local testing site that partners with STDcheck — there are over 4,500 of these across the country. You then receive your results from the convenience of home.

For those of you who would rather get tested by quickly visiting a lab near you, STDcheck is the way to go.

HIV testing sets STDcheck apart from the pack. It offers two great ways to test for HIV:

• The HIV I & II (4th generation) test works reliably 2-3 weeks after exposure. You’ll get results within 1-2 days and can consult with a doctor over the phone if your test is positive. This test can detect HIV infection sooner than older versions of HIV tests because it looks for antibodies and antigens. The antigens can be detected sooner when antibody levels are still low.
• The HIV RNA early detection test is a fantastic option for very early HIV testing, providing reliable results as soon as 11 days after exposure.27

Below is a summary of what comes in the STDcheck multi-test kits.

The biggest drawback to STDcheck’s service is that if you test positive for certain treatable STDs (namely, chlamydia, gonorrhea, or trichomoniasis), you have to pay a hefty fee for a prescription. STDcheck charges $95 for a physician consultation. Frankly, you’d be better off taking your results to LetsGetChecked for a $49 telehealth visit and saving yourself nearly $50.

If you have the ability to print your lab order at home and bring it with you to your local lab, we recommend doing so. STDcheck offers you the option to fax your lab this order, but our testers repeatedly had this process fail, and one had to return home to print their report and go back to the lab on another day.

There are a few other companies that offer at-home STD testing services that didn’t quite make our main list for one reason or another. However, there may be instances where these companies offer something very specific that suits your unique needs. So let’s take a quick look.

Nurx

Nurx is a massive company that offers everything from birth control to migraine relief. It has a trio of STI bundles that can look for chlamydia and gonorrhea (three-site), hepatitis C, syphilis, trichomoniasis, and HIV, depending on which bundle you select. It also offers HPV screening outside of its STI bundles. Interestingly, even though the company provides treatment for herpes, it doesn't have a test to detect it. Nurx accepts insurance, which can cut the cost of its bundles in half. Ultimately, we’d like to see them expand into individual test offerings and introduce screening for herpes.

There’s also a bit of potential confusion around Nurx’s pricing. The company boasts insurance coverage, which similar providers lack, and it advertises its tests as being available at a certain price, but that’s only if you have good insurance coverage. And Nurx charges a basic fee for processing your test that is not eligible for insurance coverage.

This is how the pricing with insurance actually shakes out:

If your insurance covers 100% of the cost of the test, you’ll still owe $29.50. That’s less than most similar tests from other providers, but if you have less generous insurance, it gets a little murkier.

Here’s an example: Let’s say you have decent insurance, and your provider is going to offer coinsurance coverage for Nurx tests once you’ve met your deductible. Well, if you’re still at least $220 away from meeting your deductible, you’ll be on the hook for the full cost of any Nurx test.

But maybe you have met your deductible. Many insurers offer coinsurance payments for testing, so let’s say yours is going to pay 75% of the cost. For the basic test, that leaves you with a $67 bill. And the lower your insurance’s coinsurance coverage, the more you’ll have to pay. The ultimate differences between what your insurance will cover from Nurx and what you can get with transparency from other companies have prevented us from regarding Nurx any more favorably here.

Personalabs

Personalabs is similar to STDcheck in that its services involve at-home ordering and results, but sample collection takes place in a lab. It offers one of the most extensive libraries of STD tests on the market, with a total of 27. Some of its panels are designed with specific clientele in mind, as well, like its Adult Talent Blood Test Panel, which is intended for adult film workers to take at least every 30 days.

The biggest drawback to Personalabs is that its prices are almost universally higher than those of similar tests and panels from its competitors. It offers some very specific tests that others do not, like a Treponema pallidum test used to confirm a syphilis diagnosis.