Abstract Introduction: The Canine Comparative Oncology and Genomics Consortium (CCOGC) is a non-profit entity developed to facilitate collaborations across disciplines and to focus on comparative approaches using companion animals to study cancer. One resource offered by CCOGC is the Pfizer-CCOGC Biospecimen Repository that currently houses over 2,000 highly annotated biological specimens from patients diagnosed with one of seven spontaneously arising cancers: osteosarcoma, lymphoma, melanoma, pulmonary tumors, mast cell tumor, soft tissue sarcomas and hemangiosarcoma. Samples available from each patient include tumor and healthy tissues (formalin-fixed, snap-frozen and OCT), frozen serum, plasma, urine and whole blood. This spectrum of specimens offers opportunities for genomic, proteomic, and metabolomic profiling, and for construction of tissue microarrays. This unique resource operates on a self-perpetuating model and was opened to the scientific community for peer-reviewed requests for sample withdrawal in early 2013. The goal of this internally commissioned study was to establish quality control (QC) and quality assurance (QA) parameters for external customers wishing to use this biobank. Experimental Procedures: QC and QA measures of nucleic acid integrity were obtained from 188 specimens, representing snap frozen tumor tissue and whole blood from cases selected across all seven histologies. QC scores for tumor DNA and RNA samples and blood DNA (max = 3) were assigned according to yield, integrity, and purity. The sum of these values (max = 9) was then used to assign each individual case to a category, where category A represents cases whose specimens yielded the highest overall quality score (8-9), category B those with good quality score (6-7) and category C those with the lowest overall quality score (<5). Microscopic QC and QA were completed by a panel of board-certified veterinary pathologists at the NCI, using tissues from 41 to 50 cases per histology to corroborate the original diagnosis and to estimate tumor and stromal contribution. Formalin-fixed and paraffin-embedded tumor specimens were processed into routine 5 µm sections and stained with hematoxylin and eosin for histopathology and quantitative morphometry. In selected cases, immunohistochemistry was employed to aid phenotypic assessment. All discrepant diagnoses were reviewed by >eight board-certified veterinary pathologists at the NIH to arrive at a final consensus diagnosis. New Unpublished Data: Over 90% of tumor DNA and RNA samples met criteria for categories A or B. More than 99% of blood DNA samples met criteria for categories A or B. Microscopically, the original diagnoses were corroborated for 89% (295/331) of cases. An alternate diagnosis was reached for 6% of all samples and a neoplastic process was not evident in ~5% of the samples. The three types of sarcomas and pulmonary tumors showed the greatest degree of cellular heterogeneity and stromal components, while melanomas and lymphomas were more homogeneous and generally had >70% tumor content. Nevertheless, most samples contained sufficient neoplastic representation for -omics applications. Conclusions: Independent QC and QA measures indicate that samples in the Pfizer-CCOGC Biospecimen Repository retain high nucleic acid quality and integrity. Approximately 90% of tumor specimens in the bank contain tissue consistent with the original diagnosis and are of sufficient quality for analytical pathology and for nucleic acid isolation and analysis. Citation Format: Rachael Thomas, Mark Simpson, Hiro Mochizuki, Christina Williams, Kelsey Poorman, Katie Kennedy, Christina Mazcko, Jaime F. Modiano, Matthew Breen. Quality control and quality assurance of canine biological specimens available through the Pfizer-CCOGC, Inc. National Biorepository for Comparative Oncology Studies. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A51.