ABSTRACT – BIOCORE To obtain the full panel of biomarkers in the MIDUS project, collection and analytic efforts must be coordinated. The BioCore (B) thus fulfills an essential role in MIDUS by providing centralized, reliable testing, processing, and storage of biospecimens (i.e., hematological, endocrine, inflammatory, metabolic, bone turnover, antioxidant, gene expression). All tests are performed by single laboratories to ensure consistent results over time. Core B also assists in the standardization of protocols (i.e., identical collection and processing SOPs) and monitors shipment integrity and testing at the analytic laboratories over time (i.e., Quality Control). Core B also has the primary responsibility for storing aliquots from new samples and maintaining a complete set of archival specimens in ultracold freezers. In addition to overseeing all testing, the BioCore conducts assays and transports the samples that are tested at local clinical labs in Madison, WI. A centralized Core operation is essential to ensure uniform entry of test results into a single record system. One corollary of this administrative function is reviewing the reliability of data entry before transmission of results for dissemination and combining with demographic/psychosocial data. Core B also has several advisory and pedagogical functions, which includes providing “norms” for test results, meeting with investigators to advise on analyses, and conducting educational workshops on the use and meaning of biological measures at MIDUS meetings. The future performance of the BioCore will be facilitated by the extensive experience gained during the prior MIDUS periods. The panel of biomarkers going forward is similar to the panels employed previously with some new additions. The BioCore has previously assisted in establishing new methodologies (e.g., multi-cytokine arrays, an assay of HDL anti-oxidant activity) and will also oversee new analyte testing related to risk for Alzheimer’s Disease and Related Dementias (ADRD) linked with the Ancillary U01 application. To highlight the BioCore’s level of experience, over 100,000 specimens have been tested in the prior periods. Processing of blood and/or cells for gene expression is also routine for Dr. Coe’s (PI, BioCore) laboratory. Dr. Coe has over 3 decades of prior experience with endocrine and immune assays, including with many body fluids, different assay platforms and cell separation protocols. In sum, Core B provides the infrastructure and required resources to ensure high quality and reliable biomarker assessments in MIDUS.