This study was conducted to determine optimal buffer pH, extraction procedure, and temperature for detecting central nervous system (CNS) tissue on meat surfaces and on carcass-splitting band saw blades using swab sampling. Glial fibrillary acidic protein (GFAP) is restricted to CNS tissue and has been used as a marker for CNS tissue presence in meat products. Sample preparation, extraction procedure, and extraction temperature of glial fibrillary acidic protein fluorescent enzyme-linked immunosorbent assay (GFAP F-ELISA) were modified to detect CNS tissue on meat surfaces and on carcass-splitting band saw blades. Maximum GFAP recovery was observed with an extraction buffer pH of 7.4. Extracting samples at room temperature by vortexing for 30 s in 1 ml of extraction buffer (phosphate-buffered saline [pH 7.4] plus 0.05% sodium dodecyl sulfate) consistently provided detection of GFAP on meat surfaces contaminated with 500 microg of spinal cord suspension per 50 cm2 and on carcass-splitting band saw blades contaminated with 20 microg of spinal cord suspension per 50 cm2. Recovery of GFAP was not affected by storing samples overnight at 4 degrees C. The current studies demonstrate the effectiveness of modified sampling procedures and preparations, sample extraction buffer pH, and extraction temperatures. These modifications introduced to the original F-ELISA sampling protocol result in asensitive and repeatable assay for detection of CNS tissue on meat surfaces and on carcass-splitting band saw blades.