FIG. 4.

Direct comparison of the ELISPOT and tetramer assays. (A) Both the percentage of CD8⁺ T cells and the number of positive cells per million PBMCs are shown. (B) The correlation between the numbers of PBMCs as detected by the SL9 tetramer assay (x axis) or the SL9 ELISPOT assay (y axis) is graphically represented. For the tetramer assay, the forward and side light scatter gates were enlarged to include PBMCs as counted in the hemocytometer, thereby allowing more direct comparison with the “nongated” ELISPOT assay.