P-TAU181 Assay

Advance your neurology research from discovery to the clinic by reliably detecting phosphorylated-Tau 181 (p-Tau 181) in serum, plasma, or cerebrospinal fluid (CSF).

The Quanterix Simoa® p-Tau 181 assay is an ultrasensitive laboratory assay test designed to accurately measure p-Tau 181 levels in serum, plasma, or cerebrospinal fluid (CSF) samples. This pTau-181 assay is performed using Quanterix’s Simoa® platform, a digital immunoassay technology that detects and measures low levels of biomarkers.


Benefits of using the Simoa® pTau-181 Assay

  • Highly sensitive and specific detection of p-Tau 181, allowing for early and accurate detection of neurodegenerative diseases in research applications
  • Ability to monitor disease progression and treatment response over time
  • Compatible with a range of sample types, including blood and CSF, making it a versatile p-Tau 181 assay

p-Tau 181 in Neuropathology

Tau is a microtubule-stabilizing protein primarily localized in neurons of the central nervous system but also expressed at low levels in astrocytes and oligodendrocytes. Tau consists of six isoforms in the human brain with molecular weights of 48,000 to 67,000 daltons, depending on the isoform.

Elevated tau in CSF is a hallmark of patients with neurodegenerative disease and severe head injuries, suggesting its extracellular release during neuronal damage and its role as a biomarker with specificity for brain injury. In Alzheimer’s disease (AD) and related neurodegenerative diseases, including chronic traumatic encephalopathy, tau is abnormally phosphorylated and aggregated into bundles of filaments. Threonine 181 is one of the phosphorylation sites of human tau protein (p-Tau 181). Research suggests p-Tau 181 is more strongly associated with AD markers than total tau.

Applications and Intended Use

The Quanterix Simoa® p-Tau 181 assay is validated for use in discovery and diagnostic research applications. The Simoa® p-Tau 181 assay targets the proline-rich region of the Tau protein, which is highly conserved amongst the tau isoforms. Assays are available for use on the Quanterix HD-X, HD-1, and SR-X instruments, which offer options ranging from benchtop assay prep to automated sample processing and high-throughput capabilities.
  • Research on Neurodegenerative Diseases: By measuring phosphorylated tau protein levels in the blood, researchers can gain insights into the role of ptau-181 in the disease process and develop new diagnostics and neuro-prognostics for these debilitating diseases.
  • Drug Discovery: Identify and screen promising drug candidates for further development and testing.
  • Biomarker Discovery and Validation: Researchers can use the Simoa® ptau-181 Kit to validate emerging biomarkers, providing researchers with a reliable and accurate tool for biomarker discovery workflows.

Compatible Instruments

  • Advantage Plus: HD-X
  • Advantage: HD-1/HD-X/SR-X
Simoa® pTau-181 V2.1 Assay Performance
  • Analytical LLOQ: 2.00 pg/mL
  • Functional LLOQ (serum and plasma): 8.00 pg/mL
  • Functional ULOQ (serum and plasma): 1280 pg/mL
  • Functional LLOQ (CSF): 20.0 pg/mL
  • Functional ULOQ (CSF): 12,800 pg/mL
  • LOD: 0.620 pg/mL; range 0.084-1.211 pg/mL
  • Tests per kit: 96
  • Analytical LLOQ: 2.23 pg/mL
  • Functional LLOQ (serum and plasma): 8.92 pg/mL
  • Functional ULOQ (serum and plasma): 1280 pg/mL
  • Functional LLOQ (CSF): 22.3 pg/mL
  • Functional ULOQ (CSF): 12,800 pg/mL
  • LOD: 1.04 pg/mL; range 0.146-1.750 pg/mL
  • Tests per kit: 96

Kit Contents

Our ready-to-use Simoa® kits contain all the reagents necessary to run your p-Tau 181 assays. Each kit contains enough reagents for 96 tests.

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