Our August 2022 Quick Question addresses lupus anticoagulant testing, a member of the standard thrombophilia screening profile. “You test for lupus anticoagulant [LAC] using a low-PL PTT reagent and a hex-phase high-PL mix. The mix results are 10 seconds shorter than the first test. What do you conclude?” The question illustrates the PTT-based LAC test in which the initial test employs a partial thromboplastin reagent with reduced phospholipid [PL] designed to be sensitive to LAC followed by a confirmatory hex-phase high PL reagent meant to neutralize LAC. Please answer and provide your recommendations in the comment section below.