p-Tau 205

p-Tau 205

Simoa^® p-Tau 205 Advantage PLUS (105634)

Phosphorylated tau at threonine 205 (p-Tau 205) is an emerging biomarker for Alzheimer’s disease (AD) that provides highly specific insight into the presence and progression of tau neurofibrillary tangles (NFTs), a hallmark of advanced tau pathology. Unlike other phosphorylated tau species such as p-Tau 181 and p-Tau 217, which are more closely tied to amyloid beta pathology, p-Tau 205 reflects downstream tau pathology, correlating strongly with Braak stages, cognitive decline, and regional brain atrophy.

Simoa^® p-Tau 205 immunoassay, developed on Quanterix’s Simoa HD-X Analyzer^® platform, delivers single-molecule sensitivity and scalable performance for robust detection across the Alzheimer’s continuum.

Key Benefits of the Simoa^® p-Tau 205 Assay

• Highly Specific for Late-Stage Tau Pathology: p-Tau 205 is strongly associated with mature NFTs and tau PET signal, making it a valuable biomarker for monitoring disease progression and staging in later phases of Alzheimer’s disease.
• Ultrasensitive Quantification with Simoa^®: Leveraging Quanterix’s digital immunoassay technology, the p-Tau 205 assay detects biomarkers at femtogram levels, surpassing traditional ELISA by up to 1,000-fold in sensitivity.
• Automated and Scalable on HD-X: The assay runs on the fully automated HD-X platform, offering reproducible results, high throughput.

Biological and Clinical Relevance

• Stage-Specific Biomarker: p-Tau 205 levels begin to rise during the mid-to-late stages of Alzheimer’s disease, complementing early-stage biomarkers like p-Tau 217. This temporal distinction allows researchers to differentiate phases of tau pathology more precisely.
• Cognitive and Anatomical Correlation: In clinical studies, CSF p-Tau 205 has shown strong alignment with cognitive decline, brain atrophy, and tau PET imaging, making it a promising tool for both diagnosis and therapeutic monitoring.
• Enabling Drug Development and Patient Stratification: p-Tau 205 supports precision medicine by allowing researchers and clinicians to stage disease, monitor treatment response, and select trial populations based on tau pathology burden.

Powering Tau Research with Simoa^®

The Quanterix Simoa platform delivers unmatched performance in ultra-sensitive biomarker detection. With high precision, wide dynamic range, and low background noise, the p-Tau 205 assay empowers researchers to advance:

• Alzheimer’s disease staging
• Tau pathology mapping
• Clinical trial endpoints
• Drug efficacy monitoring
• Non-invasive alternatives to tau PET

Assay Specifications

• Sample Type: CSF, serum, & plasma
• Compatible instruments: HD-X
• Analytical Lower Limit of Quantification (LLOQ): 0.2250 pg/mL
• Lower Limit of Detection (LOD): 0.0470 pg/mL

Kit Contents

The assay kit includes all necessary reagents and controls to perform 96 tests.