Table 1.

Comparison of three T-cell assays.

Assay	Advantage	Disadvantage
ELISPOT	No cell fixation	Cell of origin of cytokine production unclear
	The same cells can be retested	No sorting of cytokine-secreting cells possible
	Suitable to test many samples simultaneously
	Cytotoxicity assay can be induced
	A lower number of cells required for analysis
Intracellular cytokine staining	Assessment of multiple cytokines at single cell level	Cells have to be fixated and permeabilized
	Combination with phenotyping and cytotoxicity assay	No sorting of vital cell populations possible
MHC-multimer staining	Combination with phenotyping Sorting of antigen-specific T cells, which can be used for adoptive T-cell therapy Detection of dysfunction/non-functional antigen-specific T cells, e.g., naïve T cells	Each tetramer has to be produced for respective HLA typing and peptide
		Not suitable for the assessment of cytokine secretion (functionality)