Assay of glutamate

Blood samples were collected in vacutainer tubes. Serum separation was isolated by centrifugation at 1000 g over 15 minutes. The serum samples should always be pre-diluted 1:5 (100 µl serum + 400 µl water) and stored at 2-80C until the time of analysis.

Glutamate concentrations in serum samples were analysed using Glutamate ELISA Kit (KA1909-Abnova) according to manufacturers’ instructions and Chemwell 2910 analyser. There are three steps of the glutamate assay procedures: extraction, derivatisation and ELISA. Extraction procedures were performed manually, whereas derivatisation and ELISA were done robotically using Chemwell 2910 analyser. Limit of detection of Glutamate Elisa Kit (KA1909-Abnova) is 0.3 µg/ml or equals 2.04 µmol/L.