Feb 27, 2022

Cellular Technology Limited (CTL) leads the ELISPOT/FluoroSpot field as an all-in-one solution provider for standardised immune monitoring. CTL offers a comprehensive platform of instrumentation, reagents, and services that include, but are not limited to, top-of-the-line analysers, the largest commercially available portfolio of ELISPOT/FluoroSpot kits, an extensive library of HLA-typed cryopreserved PBMC, CD8/CD4 positive antigen controls, novel whole-well image-based cytotoxicity assays and a CLIA-certified Contract Laboratory.


Having served the immunological community for over 20 years, CTL’s core knowledge of immunology narrows the gap between basic immunology and its application in healthcare.  

Exquisite Sensitivity

ELISPOT and its variant, FluoroSpot (collectively called ImmunoSpot® Assays) detect in peripheral blood mononuclear cells (PBMC) rare antigen-specific T or B cells via their antigen-driven production of cytokines or antibodies. PBMC sit on a membrane coated with analyte-specific antibody that captures the analyte produced by the individual T or B cells in the immediate surrounding of the secreting cells, before the analyte is diluted in culture supernatant, absorbed by receptors of third-party cells, or degraded proteolytically.

ImmunoSpot® Assays are therefore able to measure analyte release by cells with a far greater sensitivity than supernatant-based tests (including ELISAs or Bead / Protein Arrays).

ImmunoSpot® Assays are also much more sensitive for detecting rare antigen-specific T and B cells than measurements using flow cytometry. It is effective for as low as a single analyte-secreting lymphocyte among one million bystander PBMC.

High Specificity

CTL has nearly 20 years of experience in defining and establishing the criteria and software solutions for recognizing antigen-specific T cell cytokine responses. ImmunoSpot® Kits are optimized to distinguish between antigen-specific responses from “background spots” from bystander cells of the innate immune system.

Our colorimetric substrates are chosen for the precision with which they are able to resolve the cytokine signature “spot” produced by each cell, allowing for a quantitative analysis, and size-based “gating” to enumerate antigen-specific responses over bystander cytokine production.

ImmunoSpot® colorimetric substrate development is standardized and optimized for a defined incubation time, further eliminating subjective determinations regarding spot development, while enabling the resolution and discrimination of adjacent and overlapping spots from crowded assay wells.


Contact us to find out more information.