SPEAR UltraDetect™ pTau 231 Biomarker Assay Kit

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 sensitivity 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.

SPEAR UltraDetect™ is an ultra-sensitive, homogeneous immunoassay platform designed for reliable detection of low-abundance protein biomarkers. Powered by SPEAR’s unique two-factor authentication mechanism and standard qPCR readout, UltraDetect assays deliver exceptional sensitivity, specificity, and precision in a fully wash-free workflow using as little as 1 µL of sample. The solution enables robust biomarker quantification for neurological and clinical research applications with simplified workflows and broad instrument compatibility.

Download this brochure to discover the fundamentals of SPEAR Technology, key features of SPEAR UltraDetect Assays, and a comprehensive summary of the complete SPEAR Solution.

Friday, January 30 at 15:00 GMT | 16:00 CET | 10:00 EST | 07:00 PST

Growing evidence shows that plasma phosphorylated tau (pTau) 217 is one of the most accurate and reliable blood-based biomarkers for identifying early Alzheimer’s disease pathology, even before the onset of clinical symptoms. As research efforts expand beyond cerebrospinal fluid (CSF) biomarkers and PET imaging, sensitive and specific plasma assays have become essential for improving early detection, supporting clinical trial design, and enabling large‑scale population screening.

In this SelectScience webinar, Dr. Nicholas Ashton of Banner Health and Dr. Laurel Provencher of Spear Bio will explore how emerging analytical innovations enhance the measurement of low-abundance plasma pTau 217, helping researchers better classify amyloid positivity, improve disease discrimination, and align blood-based results with established CSF biomarker profiles.

The webinar will compare assay performance across the BioFINDER and WRAP cohorts – two leading longitudinal studies shaping our understanding of Alzheimer’s progression. It will also highlight how the SPEAR UltraDetect™ platform from Spear Bio is designed to deliver the ultra‑sensitive, high‑specificity detection capabilities needed to support these advancements in blood-based Alzheimer’s research.

Key learning objectives:

• Identify the analytical challenges of measuring plasma pTau 217 at low concentrations and understand why enhanced sensitivity and specificity are critical for Alzheimer’s disease research.
• Understand the principles behind high‑performance pTau 217 assay workflows (such as the SPEAR UltraDetect™ assay workflow), including two-factor authentication approaches that enhance specificity and reduce off‑target signals.
• Learn how to interpret essential performance metrics commonly used to evaluate blood-based biomarkers, such as assay concordance, amyloid positivity classification, and relationships between plasma and CSF biomarkers.
• Recognize how next-generation plasma biomarker platforms can support study design, cohort stratification, and future clinical development in Alzheimer’s disease.

Who should attend?

This SelectScience webinar is ideal for scientists and decision-makers involved in neurodegenerative disease research, biomarker development, clinical study design, and analytical validation of diagnostic assays. Professionals in pharma, biotech, CROs, academic research centers, and clinical laboratories seeking to advance plasma pTau 217 detection will find this session particularly valuable.

Certificate of attendance

If you attend the live webinar, you will automatically receive a certificate of attendance, including a learning outcomes summary, for continuing education purposes. If you view the on-demand webinar, you can request a certificate of attendance by emailing editor@selectscience.net.

Webinar details

• Cost: Free to attend
• Location: Online
• Duration: 60 minutes

Registration is required to secure your place. If you register but can’t attend live, you will receive a link to the on‑demand recording once it becomes available.