Fig. 7

Assay measurements are slightly higher in serum than in plasma and are reduced in the presence of hemolysis. Blood was collected from mice 6 h after isoflurane exposure (sham) (i) or isoflurane exposure and TBI (ii) by cardiac puncture into tubes with (plasma) and without (serum) EDTA. a Plasma and serum were isolated by centrifugation and were assayed in duplicate. Differences in concentrations by matrix were analyzed by paired t test, ****p < 0.0001. b Plasma specimens were spiked with 0%, 5%, 25%, or 50% red blood cells, frozen at − 80 °C for 1 h, thawed, and assayed in duplicate. The effect of hemolysis on measured concentrations was analyzed by one-way ANOVA with repeated measures (exact p values are shown below graphs) followed by Dunnett’s multiple comparisons test, no significant differences from neat plasma were found. Mean plasma GFAP concentrations for each mouse are plotted with points representing mean and error bars ±SD of duplicates, in some cases error bars are smaller than the symbol. TBI: traumatic brain injury, EDTA: ethylenediaminetetraacetic acid, SD: standard deviation