This is an observational study that will collect blood from a finger prick (Capitainer SEP10 single channel device) and assess the accuracy of pTau-217 testing in comparison to previously collected venous blood samples from the same individuals.

Blood biomarkers offer a less invasive and cheaper method for identifying Alzheimer's disease (AD)-related pathophysiological changes. AD blood biomarkers are already being adopted by clinical practice and their use will only expand in coming years as access to AD modifying therapies increases. In addition, blood biomarkers are emerging as critical tools in AD research as they allow for streamlined identification of participants with the most relevant underlying levels of AD pathophysiology.

While blood tests offer a less invasive alternative to traditional detection methods (e.g., lumbar puncture, brain imaging), measuring biomarkers through venous blood draws can be logistically challenging, especially in resource-limited areas or for individuals unable to access specialized facilities. The use of blood collection cards could simplify the process, reduce the resources required, and make testing more accessible to a broader population. However, the accuracy of the measurement and their usability and tolerability to patients and research participants is not yet known. This study aims to evaluate acceptability of sampling using finger prick collection with a blood collection card for measuring pTau-217 as well as compare result accuracy to venous blood draw collection, thus addressing accessibility and scalability challenges in AD biomarker testing.

eDROP-AD is an ancillary study of the "Weekly blood draw study to understand the biological variability of plasma pTau-217" (Draw-10). Draw-10 is enrolling approximately 100 adults ages 50-80. Participants come to a study site weekly over a nine-week period for a venous blood draw with a phlebotomist. Participants at a select study site who provide a venous blood draw sample in Draw-10 will be invited to participate in eDROP-AD, leveraging the opportunity to evaluate the participant experience using blood collection cards and compare the results of the venous blood draw samples with blood samples acquired via the Capitainer SEP10 single channel device.

Inclusion Criteria:

• Able and willing to provide informed consent for the eDROP-AD study.
• Enrolled in the Draw-10 study at Banner Alzheimer's Institute-Phoenix and provided at least one venous blood sample.
• Able and willing to fully comply with study procedures defined in this protocol.
• Written and spoken fluency in the English language.

Exclusion Criteria:

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Draw-10 study participants at Banner Alzheimer's Institute-Phoenix

study dataset will be shared with qualified investigators

Data will be shared within 12 months after study completion