Laboratories within the LRN are divided into 3 levels:
- Sentinel labs
- Reference labs
- National labs
Any laboratory that performs microbial analysis is, by default, a sentinel laboratory. A laboratory that refers to specimens containing microbial agents or toxins is also a sentinel laboratory. These laboratories are the first responders in the line of defense, often the first to spot unusual results and alert public health and law enforcement authorities. A sentinel clinical laboratory is one of the following three types:
- Certified to perform high-complexity testing under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) by the Centers for Medicare & Medicaid Services (CMS) for the applicable specialty of microbiology - - OR - -
- A Department of Defense (DoD) laboratory certified under the DoD Clinical Laboratory Improvement Program - - OR - -
- A veterinary medical diagnostic laboratory fully accredited by the American Association of Veterinary Laboratory Diagnosticians (AAVLD)
- - AND - -
The laboratory performs Gram stain testing in-house and at least one of the following:
- Lower respiratory tract cultures
- Wound cultures
- Blood cultures
Note: The designation Sentinel Clinical Laboratory has replaced the former Basic or Advanced LRN Laboratory designations.
