The ECHO Biorepository serves as a national resource responsible for acquiring, storing and distributing ECHO specimens. The biorepository maintains quality by using standardized processes and procedures and provides a secure environment and necessary systems to receive, maintain, and distribute the ECHO specimens to approved parties. The biorepository provides management of all ECHO specimens. The ECHO specimens consist of existing collections located at a site’s local storage that sites will transfer to the biorepository and new specimens collected under the ECHO-wide Cohort Data Collection Protocol and sent directly to the biorepository. Some biospecimens to be stored in ECHO Biorepository were collected over many years from studies and are available in a finite quantity. Each ECHO biospecimen is unique and cannot be replaced if lost, damaged, or contaminated. It is very important that these biospecimens be stored under optimal conditions, which vary from type to type of biospecimen.