Galactose is an inefficient substrate for glycolysis in primary CD4+ T cells and T cell lines. A. The extracellular acidification rate (ECAR) and B. oxygen consumption rate (OCR) over time is given as a percentage of the baseline recorded at 41 minutes in the absence of carbohydrate substrate for primary CD4+ T cells from four donors, CEM-ss and Jurkat cells. Vertical lines indicate the injection of galactose, glucose or a combination of the two and oligomycin, respectively. Data from primary CD4+ T cells represent the average from four plates with one donor per plate. Data for CEM-ss and Jurkat cells are the average of three plates. Error bars represent the standard deviation and asterisks indicate p-values from ANOVA with Tukey post-test relating to the differences between cultures containing galactose only and cultures containing glucose or glucose and galactose: *0.01 < p < 0.05, **0.005 < p < 0.01, ***p < 0.005, data points without an asterisk have non-significant differences.