The "Stanford antibody test" is the Premier Biotech test (per the Stanford Daily)
This page at Johns Hopkins lists a number of serology tests and their claimed accuracy. That test has no numbers giiven.
The UK has complained that the tests they were investigating, rated at (Alltest) "Company claims up to 98.6 per cent" and (Wondfo) no claim published, were not good enough to use. "The problem is after a couple of weeks [after symptoms appear], the detection rate remains at about 50 per cent to 60 per cent, especially in asymptomatic or mildly symptomatic cases."
Some analysis of these tests can be found in this unreviewed preprint.
In Austin, one place is advertising non-FDA-approved antibody tests for $45. These are Aytu Biosciences/Orient Gene Biotech POC tests. "The sensitivity is 87.9% and specificity is 100% for IgG, and for IgM it is 97.2% and 100%, respectively." However, the manufacturer notes: "In general, antibodies can be detected 1-3 weeks after infection as there is a window period".
This page at Johns Hopkins lists a number of serology tests and their claimed accuracy. That test has no numbers giiven.
The UK has complained that the tests they were investigating, rated at (Alltest) "Company claims up to 98.6 per cent" and (Wondfo) no claim published, were not good enough to use. "The problem is after a couple of weeks [after symptoms appear], the detection rate remains at about 50 per cent to 60 per cent, especially in asymptomatic or mildly symptomatic cases."
Some analysis of these tests can be found in this unreviewed preprint.
In Austin, one place is advertising non-FDA-approved antibody tests for $45. These are Aytu Biosciences/Orient Gene Biotech POC tests. "The sensitivity is 87.9% and specificity is 100% for IgG, and for IgM it is 97.2% and 100%, respectively." However, the manufacturer notes: "In general, antibodies can be detected 1-3 weeks after infection as there is a window period".