The Government requires the continued supply of Electrochemiluminescence (ECL) analyzers, specifically the Meso Scale Diagnostics (MSD) SQ120 BT analyzer, which is the designated replacement for the obsolescing MSD PR2 1800 system. The acquisition also includes the proprietary immunoassay kits, reagents, and related consumables necessary for the system's operation in support of biological reconnaissance and surveillance missions. Meso Scale Diagnostics, LLC is the only known source capable of providing a commercially available platform that is compatible with Government-validated assays for the required toxins (Staphylococcal enterotoxin B, Botulinum toxin, and Ricin toxin). A critical and unique requirement is that the system must be safely operable outside of a primary engineering control (e.g., a biological safety cabinet) to support end-users in mobile laboratories with significant space constraints. Market research has confirmed that no other commercially available system meets this essential safety and operational requirement.