RetourT-SPOT.TB is the only ELISPOT-based IGRA test that is currently recommended by WHO. This test is produced by Oxford Immunotec, United Kingdom of Great Britain and Northern Ireland (United Kingdom). The T-SPOT.TB test requires a normalization step in which peripheral blood mononuclear cells (PBMCs) are isolated, washed and counted to ensure the reproducibility of the test. The test has four wells into which isolated PBMCs are placed. One well contains nil (for a negative control), one phytohemagglutinin (for a positive control) and two the M. tuberculosis-specific proteins (ESAT-6 and CFP-10) (54).
Fig. 3.6. T-SPOT.TB kits
Source: Reproduced with permission of Oxford Immunotec, ©2021. All rights reserved.