In 2026, memory-clinic patients have two different tools for Alzheimer's evaluation. Blood tests provide a less-invasive first check for amyloid-related signals, while Tauklarify tau PET maps tau tangles in the brain. Tauklarify (florquinitau F 18) is a brain PET imaging drug for cognitively impaired adults evaluated for Alzheimer's.
It identifies tau neurofibrillary tangle pathology, the twisted tau deposits tied to Alzheimer's disease. According to Lantheus, the FDA approved it on Aug. 14, 2026 for this use in the company approval notice.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What does each test measure?
- Who is each test meant for?
- How do clinics use them together?
- What should you ask at your visit?
What does each test measure?
Blood tests detect plasma markers linked to amyloid pathology, such as p-tau and amyloid fragments. A positive result signals that Alzheimer's pathology is likely present. It does not show where damage sits in the brain. Tau PET directly images tau tangle location and spread in the brain.
That spatial detail helps doctors stage disease and understand symptom patterns. For memory-clinic patients, blood offers the entry point while PET adds tau burden information. Tauklarify binds tau tangles during the scan and complements amyloid PET in cognitive-impairment workups. It is the second FDA-approved tau tracer after Tauvid from 2020. Amyloid PET asks if amyloid is present, while tau PET asks how far tau has spread.
Who is each test meant for?
Tauklarify is for adults with cognitive impairment who are being evaluated for Alzheimer's. Its label limits use to Alzheimer's evaluation. According to Lantheus, safety and effectiveness are not established for other tau diseases in the company approval notice. The first cleared blood test, Lumipulse G pTau217/beta-Amyloid 1-42 plasma ratio, is for adults age 55 and older with signs and symptoms.
According to the FDA, the agency cleared it on May 16, 2025 as the first blood test aiding Alzheimer's diagnosis in the FDA clearance announcement. Neither approach is cleared for screening alone without symptoms. The Alzheimer's Association guideline restricts blood biomarker testing to cognitively impaired patients seen in specialty or memory-clinic care. Testing involves shared decision-making between patient, family, and clinician.
How do clinics use them together?
Most memory clinics start with history, thinking tests, and blood work. A blood test can triage patients who need more imaging or spinal-fluid testing. This path reduces invasive procedures for some patients. Stronger blood results carry more weight.
The Alzheimer's Association guideline sets at least 90% sensitivity and 75% specificity for triage tests. Tests that replace amyloid PET or spinal-fluid testing need at least 90% sensitivity and 90% specificity. Tau PET fits later in selected cases. A doctor may order it to confirm tau burden, clarify an uncertain case, or stage disease. According to the Alzheimer's Association, blood testing belongs in specialty care with counseling about meaning and next steps in the Association guideline summary.
What should you ask at your visit?
Ask whether your symptoms and age match the cleared uses. Ask what a positive or negative blood result would change.
Ask whether tau PET would alter diagnosis, staging, or treatment eligibility. Bring practical details to the appointment: Ask about limits before testing, including non-Alzheimer's tau diseases and asymptomatic screening. Then decide together whether to start with blood testing, proceed to tau PET, or pause testing.
- list of memory symptoms, start dates, and daily effects
- full medication and supplement list
- prior brain scans, blood results, and referral notes
- a family member who can describe changes at home
