Fig. 5.

The accurate measurement of CASTs with Dextramers is independent of the acquisition instrumentation employed. CASTs in peripheral blood samples from 10 or 15 patients were measured in parallel using 3 separate instruments (A–C). Regardless of instrument manufacturer or the use of analog or digital circuitry, the measured number of Dextramer positive CD8+ T cells µl⁻¹ was consistent at high (>20), medium (>10 and <20) and low (<10) levels of CASTs for every combination of instruments. Linear regression analyses of the pooled data sets reveal R² values of 0.9923 (FC 500 versus Calibur, n= 10), 0.9556 (FC 500 versus Calibur, n= 10), and 0.9068 (Calibur versus Canto II, n= 15), demonstrating the robustness of the Dextramer reagent in measuring antigen-specific T cells with different instruments. Decuplet measurements of CASTs µl⁻¹, for each of the 10 or 15 samples were highly reproducible regardless of the instrument that was utilized (D). Error bars represent the standard deviation of the mean.