SPEAR pTau 231 immunoassay for industry-leading quantification of pTau 231 in blood

Phosphorylated tau at threonine 231 (pTau 231) is emerging as a promising blood-based biomarker for incipient Alzheimer’s disease (AD) pathology—yet the sensitivity of existing assays like Simoa® is still inadequate to reliably quantify blood pTau 231 in healthy individuals, with reported 78% and 40% detectability and quantifiability, respectively.

In this application note, we compare the analytical performance of SPEAR UltraDetect™ pTau 231 Assay with Simoa pTau 213 Advantage PLUS Assay in measuring plasma pTau 231. The SPEAR assay demonstrates higher sensitivity and precision, achieving 100% detection and 100% quantification in healthy individuals and greater precision (Average CV 4.2% vs. 13.8% for Simoa). With enhanced sen-sitivity and precision, SPEAR UltraDetect enables robust quantification of baseline and subthreshold changes in pTau 231 levels, unlocking the potential of pTau 231 as a plasma biomarker for early AD-detection and longitudinal tracking of disease progression.