How the T-SPOT.TB test works
1 small tube. 1 million ways to find the truth.2
The immune response to infection with Mycobacterium tuberculosis (MTB) is mediated predominantly through T cell activation. As part of this response, T cells are sensitised to MTB antigens and the activated effector T cells, both CD4 and CD8, produce the cytokine interferon-gamma when stimulated by these antigens. The T-SPOT.TB test uses T-SPOT technology, a modified version of the enzyme-linked immunospot (ELISPOT) methodology to enumerate M. tuberculosis-sensitised T cells by capturing interferon-gamma in the vicinity of CD4 and CD8 T cells from which it was secreted.2
When your test looks for signs of TB infection using T cells, it matters how many T cells you include. The T-SPOT.TB test, unlike other tests, uses the same number each time. And it’s a big number: 250,000 cells per well, four wells per test.2 That’s a million witnesses to infection – and a moment of truth for TB.
All of the above can now be automated using the T-Cell Select reagent kit, see below the different workflows available to perform the T-SPOT.TB test:
Comparison of the different workflows available to perform the T-SPOT.TB test, showing total hands on time, total time per sample and hands on time per sample for each of the 3 processes (note full automation timings are calculated for 48 samples).