Fig. 8

Assay measurements are unaffected by a delay in blood centrifugation to plasma but may be affected by route of blood collection. Blood was collected from mice 6 h after isoflurane exposure (sham) or isoflurane exposure and TBI by the saphenous vein and by cardiac puncture. Saphenous blood was immediately centrifuged to plasma. Blood collected by cardiac puncture was separated into two equal aliquots. One aliquot was immediately centrifuged to plasma (optimal) and one aliquot was left on ice for 4 h before centrifugation to plasma (4 h on ice). After centrifugation to plasma, samples were immediately stored at − 80 °C. Samples were assayed in duplicate. Mean plasma GFAP concentrations for each mouse are plotted with points representing mean and error bars ±SD of duplicates. The effect of blood collection and processing method on measured concentration was analyzed by paired t test; no significant differences were found. SD: standard deviation, TBI: traumatic brain injury