This is not medical advice. Please use this information at your own risk. No test is perfect. A negative test does not guarantee safety. My information below is not perfect but I’ll try to keep it up-to-date as I learn new information. Layers of protection are important to avoid infection.

Molecular Testing in General

Molecular tests are well described on the website of Johns Hopkins Center for Health Security:

“Molecular tests amplify bits of viral RNA so that viral infection can be detected using a specialized test. These tests also are referred to as nucleic acid amplification tests (NAAT). The procedure begins by taking a sample from a potentially infected person’s nose or mouth (saliva), where virus might be found. If SARS-CoV-2 is present in the sample, then even low levels of virus genomic material can be amplified into millions of copies detected during a molecular diagnostic assay.”

And here is a quote from a very useful page about the differences between molecular and rapid tests: https://www.yalemedicine.org/news/which-covid-test-is-accurate

Molecular tests are generally more accurate and mostly processed in a laboratory, which takes longer; antigen tests—or “rapid tests”—are processed pretty much anywhere, including at home, in doctors’ offices, or in pharmacies. You can get antigen test results in about 15 minutes, but they tend to be less accurate.

There are two primary brands of at-home molecular test that I’ll be discussing in this document: Metrix and Pluslife.

I also created a spreadsheet format including much of the information in this document so you can compare the details side-by-side: Molecular Testing for COVID - A Community Information Resource .

Information that applies to both Metrix and Pluslife:

Testing is done at home.
Potentially three orders of magnitude more sensitive than regular rapid tests.
Expiration dates are often a year or more in the future.
Results come back in about 30-35 minutes.
Tests check to be sure they have enough material to give a valid test result. If there is not sufficient material, an invalid test will result (does not apply as much with pooled tests).
Offers much better chance of catching pre-symptomatic or asymptomatic infection compared to regular rapid tests.
Testing devices can be run off of a sufficiently powered battery (not included). This may even work better than AC power if your AC power is not reliable.

Metrix

From website: “This product has not been FDA cleared or approved, but has been authorized for emergency use by FDA under an EUA”
Very sensitive.
Requires a reader (~$50)
Tests cost $25 each, free shipping in most instances.
Free replacement test sent quickly if an invalid test occurs.
More complicated than rapid test, but still do-able.
Test completes process in about 30 minutes. Invalid test sometimes comes up within 10 mins or so.
Pooling (using one test with multiple swabs at the same time for Metrix) is not advised by the manufacturer but some people can pool 2 tests in one. Pooling logically reduces the reliability of the test result.
No issues with border/customs.

From the Metrix website:

Why should I choose Aptitude Metrix® COVID-19 test over antigen tests? Although antigen tests are cheaper than molecular tests, they suffer from a much higher risk of yielding false results1. In consequence, FDA requires all antigen tests to be performed repeatedly over several days to improve their performance2.

However, this not only multiplies the cost, but more importantly, delays the correct diagnosis, and risks missing the optimal window for treatment.

Aptitude Metrix® tests are comparable in cost to repeat antigen testing, and put your mind at ease by delivering PCR-quality results from the get-go.

Pluslife

NOT AVAILABLE IN THE UNITED STATES.
Not FDA approved. Use at your own risk.
Very sensitive, slightly more than Metrix for COVID when using the COVID-only test.
Requires a reader called a Mini Dock (~$313, but discounts available through community websites…). Available here: https://altruan.com/products/pluslife-mini-dock-poc-nat-test-device-v-575 .
COVID tests cost $8 each + shipping extra. Available here: https://altruan.com/products/pluslife-sars-cov-2-pcr-test-kits-10-tests . (Many other types of tests available that work with the Mini Dock, including multi tests like this one handling Sars-Cov-2 / Influenza A / Influenza B test kits: https://altruan.com/products/pluslife-sars-cov-2-influenza-a-influenza-b-test-kits-10-tests. Multi tests reduce reliability for COVID results.)
No free replacement test sent if invalid test occurs.
More complicated process than Metrix, but still do-able. Feels like a little high school biology lab kit.
Very helpful unofficial FAQ here: https://virus.sucks/pluslife_en/ . Read the FAQ to learn information about discounts.
Test completes process in about 30 minutes. (15 mins for positive test)
Pooling (using one test with multiple swabs - in sequence - one at a time, for Pluslife) is not advised by the manufacturer but some people can pool 4 tests in one. Pooling logically reduces the reliability of the test result.