Treponema pallidum immobilization test

noun

Treponema pal·​li·​dum immobilization test -ˈpal-əd-əm- 

: a serological test for syphilis in which a solution containing the living causative spirochete (Treponema pallidum) is combined with serum in the presence of complement with immobilization of the active spirochetes indicating a positive result

—abbreviation TPI