Spinal cord tissue detection in comminuted beef: comparison of two immunological methods

Two commercial immunological kits for detection of central nervous system (CNS) tissue in beef were compared: ScheBo® Brai nostic™, based on CNS-specific antigen (neuron specific enolase) detection, and Ridascreen® Risk Material 10/5 test, an enzyme immunoassay for glial fibrillary acidic protein. Spinal cord (SC) was added to batches of choice, select, and utility grades of ground fresh beef shoulder clod to yield 0.0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.8, and 1.6% SC in meat. Sensitivity and specificity in detecting SC in fresh and frozen samples were determined. Both Brai nostic™ and Ridascreen® kits detected SC at claimed levels: 0.25% and 0.11%, respectively. The Ridascreen® test consistently detected SC at 0.025%, below its claimed sensitivity level, expressed for brain and SC combined. The Ridascreen® test was ∼10× more sensitive, easier, faster to run and less expensive than the Brai nostic™. Overall, quality grade had no influence on SC detection in fresh or frozen meat.